docs/frontend-architecture.md

@@ -0,0 +1,78 @@
+<!--
+SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+
+SPDX-License-Identifier: GPL-2.0-or-later
+-->
+
+# Frontend architecture
+
+The HTTP frontend is a strict TypeScript application built with esbuild. Rust
+embeds deterministic JavaScript output from `assets/web/generated`; Cargo does
+not run Node.js or contact the network.
+
+## Runtime graph
+
+`frontend/src/bootstrap.ts` is the only first-party script referenced by the
+HTML document. Its imports establish startup order for WebGL support, shared UI
+services, decoder dispatch, the local Leaflet AIS adapter, and the application
+coordinator. Leaflet and the Opus decoder remain isolated vendored scripts.
+
+Feature entries under `frontend/src/plugins` are ESM bundles. The typed plugin
+loader imports them by feature group and keeps expensive map, scheduling, and
+decoder behavior lazy. Shared code is emitted as content-hashed chunks. The
+decode-history worker is an independent entry compiled against Web Worker
+globals.
+
+Dependencies point from application and feature code toward `core` and `api`.
+`api/generated.ts` contains Rust wire formats; `api/client.ts` and focused
+parsers validate untrusted HTTP, SSE, WebSocket, and worker data before it is
+used as typed application state.
+
+## Browser host contract
+
+Separate lazy bundles cannot share module instances with the stable application
+entry, so they use three intentional host namespaces:
+
+| Global | Purpose | Mutation policy |
+| --- | --- | --- |
+| `window.trx` | Application state, core services, and feature registrations | The root is frozen; lazy features may register only their documented `modules.*` service. |
+| `window.trxPluginRuntime` | Typed decoder registration and message dispatch | Runtime object is installed once; plugins register lifecycle handlers through its API. |
+| `window.trxUi` | Notifications, confirmations, tab accessibility, and control presentation | Installed once by `ui-core.ts`; consumers call methods but do not replace them. |
+
+The WebGL adapter exposes `createTrxWebGlRenderer`, `trxParseCssColor`,
+`trxHslToRgba`, and `trxClearCssColorCache` for the application bundle. Leaflet
+adds `L.TrxAisTrackSymbol` and `L.trxAisTrackSymbol` to the vendored Leaflet
+namespace.
+
+The following transitional properties are explicitly part of the lazy-feature
+host contract and are declared in `app.ts`: `lastSpectrumData`, `lastFreqHz`,
+`currentBandwidthHz`, `ft8BaseHz`, `getDecodeHistoryRetentionMs`,
+`applyDecodeHistoryRetention`, `getDecodeRigMeta`, `renderRdsOverlays`,
+`buildAisVesselUrl`, `trxScheduleUiFrameJob`,
+`takeSchedulerControlForDecoderDisable`, `navigateToTab`, `_syncRecorderState`,
+and `refreshRdsUi`. Optional callbacks owned by lazy features are
+`refreshCwTonePicker`, `updateFt8RfDisplay`, `clearSatPredictionDom`,
+`syncWefaxToggle`, `updateAisBar`, `updateVdesBar`, `updateAprsBar`,
+`updateFt8Bar`, `updateSatLiveState`, `applyCwAutoUi`, and
+`applyCwAutoUiFromServer`.
+
+This list is closed: new standalone mutable `window` properties are not an
+accepted integration mechanism. Extend an existing typed service or introduce
+an imported interface instead. Removing transitional properties as feature
+boundaries become directly importable remains preferable.
+
+## Build and verification
+
+The generated directory is removed before every build, preventing orphaned
+compatibility bundles. Stable feature entry names are allowlisted by the Rust
+asset manifest; shared chunks use content hashes. The generic Rust handler
+rejects unknown names and unsupported MIME types and serves embedded assets
+with compression, ETags, and immutable caching.
+
+CI installs from `package-lock.json`, caches only npm downloads, type-checks the
+window and worker environments separately, lints, runs unit and DOM tests,
+starts the application in Chromium, regenerates Rust contracts and bundles,
+checks for drift, and runs REUSE validation after generation.
+
+See `frontend/src/README.md` for local commands and
+`docs/ts-migration-plan.md` for the migration decisions and completion gates.

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/app.js

@@ -939,52 +939,6 @@ var runtime = {
 };
 window.trxPluginRuntime = runtime;
 
-// src/plugin-loader.ts
-var pluginGroups = {
-  "digital-modes": ["/ft8.js", "/ft4.js", "/ft2.js", "/wspr.js", "/cw.js", "/background-decode.js", "/sat.js", "/wefax.js"],
-  "map-data": ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js"],
-  map: ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js", "/sat.js", "/sat-scheduler.js"],
-  statistics: ["/map-core.js"],
-  bookmarks: ["/bookmarks.js"],
-  recorder: [],
-  settings: ["/vchan.js", "/scheduler.js"]
-};
-var loaded = /* @__PURE__ */ new Set();
-var loading = /* @__PURE__ */ new Map();
-async function loadPlugin(path) {
-  if (loaded.has(path)) return;
-  const pending = loading.get(path);
-  if (pending) return pending;
-  const request = import(path).then(() => {
-    loaded.add(path);
-    loading.delete(path);
-  }).catch((error) => {
-    loading.delete(path);
-    throw new Error(`Failed to load plugin module: ${path}`, { cause: error });
-  });
-  loading.set(path, request);
-  return request;
-}
-async function loadPlugins(group) {
-  if (!(group in pluginGroups)) return;
-  for (const path of pluginGroups[group]) await loadPlugin(path);
-}
-function requestPlugins(group) {
-  void loadPlugins(group).catch((error) => {
-    console.error(error);
-  });
-}
-var loaderWindow = window;
-loaderWindow.loadEagerPlugins = async () => {
-  await Promise.all(["digital-modes", "map-data", "bookmarks", "settings"].map(loadPlugins));
-};
-loaderWindow.loadPluginsForTab = loadPlugins;
-document.addEventListener("click", (event) => {
-  if (!(event.target instanceof Element)) return;
-  const tab = event.target.closest("[data-tab]")?.dataset.tab;
-  if (tab) requestPlugins(tab);
-});
-
 // src/leaflet-ais-tracksymbol.ts
 (function() {
   const leaflet = globalThis.L;
@@ -1605,6 +1559,60 @@ function estimateNoiseFloorDb(bins) {
   return nthElement(bins, Math.floor(bins.length * 0.15));
 }
 
+// src/plugin-loader.ts
+var pluginGroups = {
+  "digital-modes": ["/ft8.js", "/ft4.js", "/ft2.js", "/wspr.js", "/cw.js", "/background-decode.js", "/sat.js", "/wefax.js"],
+  "map-data": ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js"],
+  map: ["/map-core.js", "/ais.js", "/vdes.js", "/aprs.js", "/hf-aprs.js", "/sat.js", "/sat-scheduler.js"],
+  statistics: ["/map-core.js"],
+  bookmarks: ["/bookmarks.js"],
+  recorder: [],
+  settings: ["/vchan.js", "/scheduler.js"]
+};
+var loaded = /* @__PURE__ */ new Set();
+var loading = /* @__PURE__ */ new Map();
+async function loadPlugin(path) {
+  if (loaded.has(path)) return;
+  const pending = loading.get(path);
+  if (pending) return pending;
+  const request = import(path).then(() => {
+    loaded.add(path);
+    loading.delete(path);
+  }).catch((error) => {
+    loading.delete(path);
+    throw new Error(`Failed to load plugin module: ${path}`, { cause: error });
+  });
+  loading.set(path, request);
+  return request;
+}
+async function loadPlugins(group) {
+  if (!(group in pluginGroups)) return;
+  for (const path of pluginGroups[group]) await loadPlugin(path);
+}
+async function loadEagerPlugins() {
+  await Promise.all(["digital-modes", "map-data", "bookmarks", "settings"].map(loadPlugins));
+}
+async function loadPluginsForTab(tab) {
+  await loadPlugins(tab);
+}
+
+// src/api/client.ts
+function isRecord(value) {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+function isRigSnapshot(value) {
+  if (!isRecord(value) || !isRecord(value.info) || !isRecord(value.status)) {
+    return false;
+  }
+  const { info, status } = value;
+  return typeof value.initialized === "boolean" && typeof info.manufacturer === "string" && typeof info.model === "string" && isRecord(status.freq) && typeof status.freq.hz === "number" && (typeof status.mode === "string" || isRecord(status.mode)) && typeof status.tx_en === "boolean";
+}
+function isRigListResponse(value) {
+  return isRecord(value) && (value.active_remote === null || typeof value.active_remote === "string") && Array.isArray(value.rigs) && value.rigs.every(
+    (rig) => isRecord(rig) && typeof rig.remote === "string" && typeof rig.manufacturer === "string" && typeof rig.model === "string" && Array.isArray(rig.supported_modes) && typeof rig.tx === "boolean" && typeof rig.filter_controls === "boolean" && typeof rig.initialized === "boolean"
+  );
+}
+
 // src/app.ts
 function requiredElement(id) {
   const element = document.getElementById(id);
@@ -1614,6 +1622,41 @@ function requiredElement(id) {
 function isFiniteNumber(value) {
   return typeof value === "number" && Number.isFinite(value);
 }
+function primitiveString(value) {
+  return typeof value === "string" || typeof value === "number" || typeof value === "boolean" ? String(value) : "";
+}
+function isRecord2(value) {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+function parseJsonUnknown(source) {
+  return JSON.parse(source);
+}
+function messageEventData(event) {
+  const data = event.data;
+  if (typeof data !== "string") throw new TypeError("Expected a text event payload");
+  return data;
+}
+async function responseJsonUnknown(response) {
+  return await response.json();
+}
+function isAppUpdate(value) {
+  return isRecord2(value) && (value.status === void 0 || isRecord2(value.status));
+}
+function isAudioStreamInfo(value) {
+  return isRecord2(value) && typeof value.sample_rate === "number" && typeof value.channels === "number";
+}
+function isRecorderActiveList(value) {
+  return Array.isArray(value) && value.every((entry) => isRecord2(entry) && typeof entry.rig_id === "string" && typeof entry.path === "string" && typeof entry.started_at === "number");
+}
+function isRecorderFileList(value) {
+  return Array.isArray(value) && value.every((entry) => isRecord2(entry) && typeof entry.name === "string" && typeof entry.size === "number");
+}
+function isRdsData(value) {
+  return isRecord2(value);
+}
+function isVchanRdsEntry(value) {
+  return isRecord2(value) && typeof value.id === "string" && (value.rds === void 0 || value.rds === null || isRdsData(value.rds)) && (value.signal_db === void 0 || value.signal_db === null || typeof value.signal_db === "number");
+}
 void loadDecoderRegistry(refreshOperatorLayoutCapabilities);
 var authRole = null;
 var authEnabled = true;
@@ -1731,7 +1774,6 @@ function applyAuthRestrictions() {
     const txLimitBtn2 = document.getElementById("tx-limit-btn");
     const txAudioBtn2 = document.getElementById("tx-audio-btn");
     const txLimitRow2 = document.getElementById("tx-limit-row");
-    const vfoPicker2 = document.getElementById("vfo-picker");
     const jogUp = document.getElementById("jog-up");
     const jogDown = document.getElementById("jog-down");
     const jogButtons = document.querySelectorAll(".jog-step button");
@@ -1809,7 +1851,7 @@ function applyCapabilities(caps) {
   if (txAudioBtn2) txAudioBtn2.style.display = caps.tx ? "" : "none";
   if (txVolControl) txVolControl.style.display = caps.tx ? "" : "none";
   if (!caps.tx && typeof stopTxAudio === "function" && txActive) {
-    stopTxAudio();
+    void stopTxAudio();
   }
   const txLimitRow2 = document.getElementById("tx-limit-row");
   if (txLimitRow2) txLimitRow2.style.display = caps.tx_limit ? "" : "none";
@@ -2063,7 +2105,6 @@ function decodeHistoryMapRenderingDeferred() {
 }
 var lastSpectrumData = null;
 window.lastSpectrumData = null;
-var lastControl;
 var lastTxEn = null;
 var lastHasTx = true;
 var lastRendered = null;
@@ -2659,7 +2700,7 @@ function applyRigList(activeRigId, rigIds, displayNames = {}) {
     window.trx.modules.scheduler?.setRig(lastActiveRigId);
     window.trx.modules.backgroundDecode?.setRig(lastActiveRigId);
     window.trx.modules.bookmarks?.populateScopePicker();
-    window.trx.modules.bookmarks?.fetch(document.getElementById("bm-category-filter")?.value || "");
+    void window.trx.modules.bookmarks?.fetch(document.getElementById("bm-category-filter")?.value || "");
   }
   window.trx.modules.map?.updateMapRigFilter();
 }
@@ -2667,8 +2708,9 @@ async function refreshRigList() {
   try {
     const resp = await fetch("/rigs", { cache: "no-store" });
     if (!resp.ok) return;
-    const data = await resp.json();
+    const data = await responseJsonUnknown(resp);
-    const rigs = Array.isArray(data.rigs) ? data.rigs : [];
+    if (!isRigListResponse(data)) return;
+    const rigs = data.rigs;
     const rigIds = rigs.map((r) => r.remote).filter(Boolean);
     const displayNames = {};
     rigs.forEach((r) => {
@@ -2684,7 +2726,7 @@ async function refreshRigList() {
     });
     serverRigs = rigs;
     refreshOperatorLayoutCapabilities();
-    serverActiveRigId = data.active_remote || null;
+    serverActiveRigId = data.active_remote;
     applyRigList(data.active_remote, rigIds, displayNames);
     window.trx.modules.map?.syncAprsReceiverMarker();
   } catch (e) {
@@ -2740,8 +2782,7 @@ var overviewWfTexPushCount = 0;
 var overviewWfTexPalKey = "";
 var overviewWfTexReady = false;
 function cssColorToRgba(color, alphaMul = 1) {
-  const parser = typeof window.trxParseCssColor === "function" ? window.trxParseCssColor : null;
+  const parsed = typeof window.trxParseCssColor === "function" ? window.trxParseCssColor(color) : [0, 0, 0, 1];
-  const parsed = parser ? parser(color) : [0, 0, 0, 1];
   return [
     parsed[0] ?? 0,
     parsed[1] ?? 0,
@@ -2769,7 +2810,7 @@ function overviewWfResetTextureCache() {
   overviewWfTexReady = false;
 }
 function overviewWfPaletteKey(pal, viewKey = "") {
-  return `${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
+  return `${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
 }
 function resizeHeaderSignalCanvas() {
   if (!ensureOverviewCanvasBackingStore()) return;
@@ -2837,7 +2878,7 @@ function drawSignalOverlay() {
   const bwStroke = BW_OVERLAY_COLORS.stroke;
   const bwHard = BW_OVERLAY_COLORS.hard;
   const bmRef = window.trx.modules.bookmarks?.overlayList ?? null;
-  if (Array.isArray(bmRef) && bmRef.length > 0) {
+  if (bmRef && bmRef.length > 0) {
     const colorMap = bmCategoryColorMap();
     const grouped = /* @__PURE__ */ new Map();
     for (const bm of bmRef) {
@@ -2847,8 +2888,9 @@ function drawSignalOverlay() {
       const x = hzToX(f);
       if (!isFiniteNumber(x) || x < 0 || x > W) continue;
       const color = colorMap[bm?.category || ""] || BOOKMARK_MARKER_FALLBACK;
-      if (!grouped.has(color)) grouped.set(color, []);
+      const segments = grouped.get(color) ?? [];
-      grouped.get(color).push(x, 0, x, H);
+      segments.push(x, 0, x, H);
+      grouped.set(color, segments);
     }
     for (const [color, segments] of grouped.entries()) {
       if (!Array.isArray(segments) || segments.length === 0) continue;
@@ -3138,7 +3180,7 @@ function waterfallColorRgba(db, pal, minDb, maxDb) {
 var _wfLutKey = "";
 var _wfLut = new Uint8Array(256 * 4);
 function ensureWaterfallLut(pal, minDb, maxDb) {
-  const key = `${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${minDb}|${maxDb}|${waterfallGamma}`;
+  const key = `${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${minDb}|${maxDb}|${waterfallGamma}`;
   if (key === _wfLutKey) return;
   _wfLutKey = key;
   for (let i = 0; i < 256; i++) {
@@ -3256,7 +3298,7 @@ function renderRdsOverlays() {
     el.innerHTML = html;
     el.addEventListener("click", (evt) => {
       evt.stopPropagation();
-      copyRdsPsToClipboard(entry.rds, entry.freq_hz);
+      void copyRdsPsToClipboard(entry.rds, entry.freq_hz);
     });
     el.addEventListener("mouseenter", () => {
       el.style.zIndex = String(entries.length + 10);
@@ -3915,7 +3957,7 @@ function updateJogStepSupport(cap) {
 }
 function normalizeMode(modeVal) {
   if (typeof modeVal === "string") return modeVal;
-  if (modeVal && typeof modeVal === "object") {
+  if (isRecord2(modeVal)) {
     const entries = Object.entries(modeVal);
     if (entries.length > 0) {
       const firstEntry = entries[0];
@@ -4436,7 +4478,7 @@ function render(update) {
       }
       lastModeName = modeUpper2;
       if (lastSpectrumData && !update.filter) {
-        applyBwDefaultForMode(mode, false);
+        void applyBwDefaultForMode(mode, false);
       }
     }
     updateWfmControls();
@@ -4590,7 +4632,6 @@ function render(update) {
     powerBtn.setAttribute("aria-pressed", "false");
     powerHint.textContent = "State unknown";
   }
-  lastControl = update.enabled;
   if (update.status && update.status.tx && typeof update.status.tx.limit === "number") {
     txLimitInput.value = String(update.status.tx.limit);
     txLimitRow.style.display = "";
@@ -4725,9 +4766,10 @@ async function pollFreshSnapshot() {
     const statusUrl = lastActiveRigId ? `/status?remote=${encodeURIComponent(lastActiveRigId)}` : "/status";
     const resp = await fetch(statusUrl, { cache: "no-store" });
     if (!resp.ok) return;
-    const data = await resp.json();
+    const data = await responseJsonUnknown(resp);
+    if (!isRigSnapshot(data)) return;
     render(data);
-    refreshRigList();
+    void refreshRigList();
     lastEventAt = Date.now();
   } catch (e) {
   }
@@ -4742,7 +4784,7 @@ function connect() {
   }
   stopMeterStreaming();
   startMeterStreaming();
-  pollFreshSnapshot();
+  void pollFreshSnapshot();
   const eventsUrl = lastActiveRigId ? `/events?remote=${encodeURIComponent(lastActiveRigId)}` : "/events";
   es = new EventSource(eventsUrl);
   const source = es;
@@ -4751,13 +4793,14 @@ function connect() {
     setConnLostOverlay(false);
     if (tabMainEl) tabMainEl.classList.remove("server-disconnected");
     if (!aboutUptimeStart) aboutUptimeStart = Date.now();
-    pollFreshSnapshot();
+    void pollFreshSnapshot();
-    refreshRigList();
+    void refreshRigList();
   };
   source.onmessage = (evt) => {
     try {
       if (evt.data === lastRendered) return;
-      const data = JSON.parse(evt.data);
+      const data = parseJsonUnknown(evt.data);
+      if (!isAppUpdate(data)) throw new TypeError("Unexpected status event shape");
       lastRendered = evt.data;
       render(data);
       lastEventAt = Date.now();
@@ -4777,21 +4820,22 @@ function connect() {
   });
   source.addEventListener("session", (evt) => {
     try {
-      const d = JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
-      sseSessionId = d.session_id || null;
+      const d = parseJsonUnknown(eventData);
+      sseSessionId = isRecord2(d) && typeof d.session_id === "string" ? d.session_id : null;
     } catch (_) {
     }
-    window.trx.modules.vchan?.handleSession(evt.data);
+    window.trx.modules.vchan?.handleSession(messageEventData(evt));
   });
   source.addEventListener("channels", (evt) => {
-    window.trx.modules.vchan?.handleChannels(evt.data);
+    window.trx.modules.vchan?.handleChannels(messageEventData(evt));
   });
   source.onerror = () => {
     if (source.readyState === EventSource.CLOSED) {
       powerHint.textContent = "trx-client connection lost, retrying…";
       setConnLostOverlay(true, "trx-client connection lost", "Retrying…", true);
       source.close();
-      pollFreshSnapshot();
+      void pollFreshSnapshot();
       scheduleReconnect(1e3);
     }
   };
@@ -4801,7 +4845,7 @@ function connect() {
       powerHint.textContent = "trx-client connection lost, retrying…";
       setConnLostOverlay(true, "trx-client connection lost", "Retrying…", true);
       source.close();
-      pollFreshSnapshot();
+      void pollFreshSnapshot();
       scheduleReconnect(250);
     }
   }, 5e3);
@@ -4915,7 +4959,7 @@ async function switchRigFromSelect(selectEl) {
     window.trxUi?.setActiveRig(lastActiveRigId);
     window.trx.modules.scheduler?.setRig(lastActiveRigId);
     window.trx.modules.backgroundDecode?.setRig(lastActiveRigId);
-    window.trx.modules.bookmarks?.fetch(document.getElementById("bm-category-filter")?.value || "");
+    void window.trx.modules.bookmarks?.fetch(document.getElementById("bm-category-filter")?.value || "");
     window.trx.modules.map?.syncAprsReceiverMarker();
     connect();
     stopSpectrumStreaming();
@@ -4940,7 +4984,7 @@ async function switchRigFromSelect(selectEl) {
 }
 if (headerRigSwitchSelect) {
   headerRigSwitchSelect.addEventListener("change", () => {
-    switchRigFromSelect(headerRigSwitchSelect);
+    void switchRigFromSelect(headerRigSwitchSelect);
   });
 }
 function setControlPending(control, pending) {
@@ -5037,7 +5081,7 @@ if (centerFreqEl) {
     centerFreqDirty = true;
     if (e.key === "Enter") {
       e.preventDefault();
-      applyCenterFreqFromInput();
+      void applyCenterFreqFromInput();
     } else if (e.key === "Escape") {
       centerFreqDirty = false;
       refreshCenterFreqDisplay();
@@ -5382,18 +5426,18 @@ if (spectrumBwInput) {
   spectrumBwInput.addEventListener("keydown", (e) => {
     if (e.key === "Enter") {
       e.preventDefault();
-      applyBandwidthFromInput();
+      void applyBandwidthFromInput();
     }
   });
 }
 if (spectrumBwSetBtn) {
   spectrumBwSetBtn.addEventListener("click", () => {
-    applyBandwidthFromInput();
+    void applyBandwidthFromInput();
   });
 }
 if (spectrumBwAutoBtn) {
   spectrumBwAutoBtn.addEventListener("click", () => {
-    applyAutoBandwidth();
+    void applyAutoBandwidth();
   });
 }
 if (spectrumBwSweetBtn) {
@@ -5466,7 +5510,9 @@ function navigateToTab(name, options = {}) {
     updateTabHistory(name, replaceHistory);
   }
   scheduleSpectrumLayout();
-  if (typeof window.loadPluginsForTab === "function") window.loadPluginsForTab(name);
+  void loadPluginsForTab(name).catch((error) => {
+    console.error(error);
+  });
   if (name === "map") {
     _initMapWhenReady();
   }
@@ -5474,7 +5520,7 @@ function navigateToTab(name, options = {}) {
     window.trx.modules.map?.scheduleStatsRender();
   }
   if (name === "recorder") {
-    refreshRecorderStatus();
+    void refreshRecorderStatus();
   }
 }
 window.navigateToTab = navigateToTab;
@@ -5604,7 +5650,7 @@ requiredElement("auth-form").addEventListener("submit", async (e) => {
 });
 var guestBtn = document.getElementById("auth-guest-btn");
 if (guestBtn) {
-  guestBtn.addEventListener("click", async () => {
+  guestBtn.addEventListener("click", () => {
     authRole = "rx";
     requiredElement("auth-passphrase").value = "";
     hideAuthGate();
@@ -5630,7 +5676,7 @@ if (headerAuthBtn) {
   });
 }
 var trxState = /* @__PURE__ */ Object.create(null);
-var trxModules = /* @__PURE__ */ Object.create(null);
+var trxModules = {};
 Object.defineProperties(trxState, {
   serverLat: { get() {
     return serverLat;
@@ -5804,8 +5850,10 @@ Object.defineProperties(trxState, {
   } }
 });
 window.trx = Object.freeze({ state: trxState, core: trxCore, modules: trxModules });
-if (typeof window.loadEagerPlugins === "function") window.loadEagerPlugins();
+void loadEagerPlugins().catch((error) => {
-initializeApp();
+  console.error(error);
+});
+void initializeApp();
 window.addEventListener("resize", resizeHeaderSignalCanvas);
 function bookmarkDistanceText(bm) {
   if (!bm || serverLat == null || serverLon == null) return null;
@@ -5830,7 +5878,7 @@ function buildBookmarkTooltipText(bm) {
 }
 function nearestBookmarkForHz(hz, widthPx, range) {
   const ref = window.trx.modules.bookmarks?.overlayList ?? null;
-  if (!Array.isArray(ref) || !isFiniteNumber(hz) || !widthPx || !range || !isFiniteNumber(range.visSpanHz) || range.visSpanHz <= 0) {
+  if (!ref || !isFiniteNumber(hz) || !widthPx || !range || !isFiniteNumber(range.visSpanHz) || range.visSpanHz <= 0) {
     return null;
   }
   const maxDeltaHz = Math.max(range.visSpanHz / widthPx * 6, 10);
@@ -5951,7 +5999,6 @@ var wfmDeemphasisEl = document.getElementById("wfm-deemphasis");
 var wfmAudioModeEl = document.getElementById("wfm-audio-mode");
 var wfmDenoiseEl = document.getElementById("wfm-denoise");
 var sdrSettingsRowEl = document.getElementById("sdr-settings-row");
-var sdrGainControlsEl = document.getElementById("sdr-gain-controls");
 var sdrGainEl = document.getElementById("sdr-gain-db");
 var sdrGainSetBtn = document.getElementById("sdr-gain-set");
 var sdrLnaGainControlsEl = document.getElementById("sdr-lna-gain-controls");
@@ -6056,7 +6103,7 @@ function levelFromChannels(channels, frameCount) {
   return Math.min(100, rms * 220);
 }
 function normalizeWfmDenoiseLevel(value) {
-  const next = String(value ?? "").toLowerCase();
+  const next = primitiveString(value).toLowerCase();
   if (next === "off" || next === "auto" || next === "low" || next === "medium" || next === "high") return next;
   return "auto";
 }
@@ -6282,7 +6329,7 @@ function resetTxTimeout() {
   if (txTimeoutTimer) clearTimeout(txTimeoutTimer);
   txTimeoutTimer = setTimeout(() => {
     console.warn("PTT safety timeout — stopping TX");
-    stopTxAudio();
+    void stopTxAudio();
   }, TX_TIMEOUT_SECS * 1e3);
 }
 function startTxTimeoutCountdown() {
@@ -6441,7 +6488,9 @@ function startRxAudio() {
   audioWs.onmessage = (evt) => {
     if (typeof evt.data === "string") {
       try {
-        configureRxStream(JSON.parse(evt.data));
+        const info = parseJsonUnknown(evt.data);
+        if (!isAudioStreamInfo(info)) throw new TypeError("Unexpected audio stream metadata");
+        configureRxStream(info);
       } catch (e) {
         console.error("Audio stream info parse error", e);
       }
@@ -6518,7 +6567,7 @@ function startRxAudio() {
   };
   audioWs.onclose = () => {
     if (txActive) {
-      stopTxAudio();
+      void stopTxAudio();
     }
     rxActive = false;
     window.trxUi?.setButtonState(rxAudioBtn, { active: false, activeLabel: "Stop Audio", inactiveLabel: "Play Audio" });
@@ -6559,7 +6608,7 @@ function stopRxAudio() {
     audioWs = null;
   }
   if (audioCtx) {
-    audioCtx.close();
+    void audioCtx.close();
     audioCtx = null;
   }
   updateWfmControls();
@@ -6587,7 +6636,7 @@ function stopRxAudio() {
 }
 function startTxAudio() {
   if (txActive) {
-    stopTxAudio();
+    void stopTxAudio();
     return;
   }
   if (!hasWebCodecs) {
@@ -6780,12 +6829,15 @@ async function refreshRecorderStatus() {
       fetch("/api/recorder/files")
     ]);
     if (statusResp.ok) {
-      const active = await statusResp.json();
+      const active = await responseJsonUnknown(statusResp);
-      renderRecorderActive(active);
+      if (isRecorderActiveList(active)) renderRecorderActive(active);
     }
     if (filesResp.ok) {
-      _recorderFiles = await filesResp.json();
+      const files = await responseJsonUnknown(filesResp);
-      renderRecorderFiles();
+      if (isRecorderFileList(files)) {
+        _recorderFiles = files;
+        renderRecorderFiles();
+      }
     }
   } catch (e) {
     console.error("Recorder status fetch failed", e);
@@ -6923,10 +6975,8 @@ function renderRecorderFiles() {
       row.parentNode?.insertBefore(playerRow, row.nextSibling);
       btn.setAttribute("aria-expanded", "true");
       btn.textContent = "Hide";
-      try {
+      void audio.play().catch(() => {
-        audio.play();
+      });
-      } catch (_) {
-      }
     });
   });
   el.querySelectorAll(".rec-delete-btn").forEach(function(btn) {
@@ -7011,7 +7061,6 @@ if (sdrSquelchEl) {
 }
 requiredElement("copyright-year").textContent = String((/* @__PURE__ */ new Date()).getFullYear());
 var decodeSource = null;
-var decodeConnected = false;
 var decodeHistoryWorker = null;
 function setModeBoundDecodeStatus(el, activeModes, inactiveText, connectedText) {
   if (!el) return;
@@ -7215,9 +7264,10 @@ function connectDecode() {
     decodeHistoryWorker = worker;
     worker.onmessage = (evt) => {
       if (historySettled || worker !== decodeHistoryWorker) return;
-      const data = evt?.data || {};
+      const data = evt.data;
+      if (!isRecord2(data) || typeof data.type !== "string") return;
       if (data.type === "status") {
-        const phase = String(data.phase || "");
+        const phase = primitiveString(data.phase);
         if (phase === "fetching") {
           setDecodeHistoryOverlayVisible(true, "Loading decode history…", "Fetching recent decodes from the client buffer");
         } else if (phase === "decoding") {
@@ -7235,7 +7285,8 @@ function connectDecode() {
         return;
       }
       if (data.type === "group") {
-        enqueueDecodeHistoryGroup(String(data.kind || ""), data.messages);
+        const messages = Array.isArray(data.messages) ? data.messages.filter((message) => isRecord2(message) && typeof message.type === "string") : [];
+        enqueueDecodeHistoryGroup(typeof data.kind === "string" ? data.kind : "", messages);
         return;
       }
       if (data.type === "done") {
@@ -7246,7 +7297,7 @@ function connectDecode() {
         return;
       }
       if (data.type === "error") {
-        console.error("Decode history worker failed", data.message || "unknown worker failure");
+        console.error("Decode history worker failed", typeof data.message === "string" ? data.message : "unknown worker failure");
         terminateDecodeHistoryWorker();
         startDecodeHistoryFallback();
       }
@@ -7268,21 +7319,21 @@ function connectDecode() {
   decodeSource = new EventSource("/decode");
   const source = decodeSource;
   source.onopen = () => {
-    decodeConnected = true;
     updateDecodeStatus("Connected, listening for packets");
   };
   source.onmessage = (evt) => {
     try {
-      const msg = JSON.parse(evt.data);
+      const msg = parseJsonUnknown(evt.data);
-      if (historySettled) dispatchDecodeMessage(msg);
+      if (!isRecord2(msg) || typeof msg.type !== "string") return;
-      else liveBuffer.push(msg);
+      const decoded = { ...msg, type: msg.type };
+      if (historySettled) dispatchDecodeMessage(decoded);
+      else liveBuffer.push(decoded);
     } catch (e) {
     }
   };
   source.onerror = () => {
     const wasClosed = source.readyState === 2;
     source.close();
-    decodeConnected = false;
     terminateDecodeHistoryWorker();
     if (!historySettled) flushLiveBuffer();
     if (wasClosed) {
@@ -7612,11 +7663,12 @@ function startSpectrumStreaming() {
   };
   source.addEventListener("b", (evt) => {
     try {
-      const commaA = evt.data.indexOf(",");
+      const eventData = messageEventData(evt);
-      const commaB = evt.data.indexOf(",", commaA + 1);
+      const commaA = eventData.indexOf(",");
-      const centerHz = Number(evt.data.slice(0, commaA));
+      const commaB = eventData.indexOf(",", commaA + 1);
-      const sampleRate = Number(evt.data.slice(commaA + 1, commaB));
+      const centerHz = Number(eventData.slice(0, commaA));
-      const b64 = evt.data.slice(commaB + 1);
+      const sampleRate = Number(eventData.slice(commaA + 1, commaB));
+      const b64 = eventData.slice(commaB + 1);
       const hadSpectrum = !!lastSpectrumData;
       const bins = decodeBase64Int8(b64);
       const rds = lastSpectrumData?.rds;
@@ -7652,7 +7704,9 @@ function startSpectrumStreaming() {
   });
   source.addEventListener("rds", (evt) => {
     try {
-      const rds = evt.data === "null" ? void 0 : JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
+      const value = eventData === "null" ? void 0 : parseJsonUnknown(eventData);
+      const rds = value !== void 0 && isRdsData(value) ? value : null;
       if (lastSpectrumData) lastSpectrumData.rds = rds;
       updateRdsPsOverlay(rds ?? null);
     } catch (_) {
@@ -7660,22 +7714,20 @@ function startSpectrumStreaming() {
   });
   source.addEventListener("rds_vchan", (evt) => {
     try {
-      const payload = evt.data === "null" ? [] : JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
+      const value = eventData === "null" ? [] : parseJsonUnknown(eventData);
+      const payload = Array.isArray(value) ? value.filter(isVchanRdsEntry) : [];
       const next = /* @__PURE__ */ new Map();
       const nextSig = /* @__PURE__ */ new Map();
-      if (Array.isArray(payload)) {
+      payload.forEach((entry) => {
-        payload.forEach((entry) => {
+        next.set(entry.id, entry.rds ?? null);
-          if (entry && entry.id) {
+        if (typeof entry.signal_db === "number") nextSig.set(entry.id, entry.signal_db);
-            next.set(entry.id, entry.rds ?? null);
+      });
-            if (typeof entry.signal_db === "number") nextSig.set(entry.id, entry.signal_db);
-          }
-        });
-      }
       vchanRdsById = next;
       vchanSignalDbById = nextSig;
       const virtualChannelId = window.trx.modules.vchan?.activeId;
       if (virtualChannelId && nextSig.has(virtualChannelId)) {
-        sigLastDbm = nextSig.get(virtualChannelId);
+        sigLastDbm = nextSig.get(virtualChannelId) ?? null;
         refreshSigStrengthDisplay();
       }
       updateRdsPsOverlay(primaryRds);
@@ -7758,8 +7810,8 @@ function startMeterStreaming() {
   meterSource = new EventSource(url);
   meterSource.onmessage = (evt) => {
     try {
-      const { sig } = JSON.parse(evt.data);
+      const value = parseJsonUnknown(evt.data);
-      applyMeterSample(sig);
+      if (isRecord2(value) && typeof value.sig === "number") applyMeterSample(value.sig);
     } catch (_) {
     }
   };
@@ -7794,10 +7846,10 @@ function clearSpectrumCanvas() {
   }
 }
 function formatOverlayPs(ps) {
-  return String(ps ?? "").slice(0, 8).padEnd(8, "_").replaceAll(" ", "_");
+  return primitiveString(ps).slice(0, 8).padEnd(8, "_").replaceAll(" ", "_");
 }
 function formatPsHtml(ps) {
-  const clipped = String(ps ?? "").slice(0, 8);
+  const clipped = primitiveString(ps).slice(0, 8);
   let html = "";
   for (let i = 0; i < 8; i += 1) {
     const ch = clipped[i];
@@ -7813,8 +7865,10 @@ function formatOverlayPi(pi) {
   return pi != null ? `PI 0x${Number(pi).toString(16).toUpperCase().padStart(4, "0")}` : "PI --";
 }
 function formatOverlayPty(pty, ptyName) {
-  if (ptyName) return ptyName;
+  const name = primitiveString(ptyName);
-  return pty != null ? String(pty) : "--";
+  if (name) return name;
+  const code = primitiveString(pty);
+  return code || "--";
 }
 function overlayTrafficFlagHtml(label, active) {
   const stateClass = active === true ? "rds-flag-active" : "rds-flag-inactive";
@@ -7913,13 +7967,13 @@ async function copyRdsRawToClipboard() {
 var rdsPsValueEl = document.getElementById("rds-ps");
 if (rdsPsValueEl) {
   rdsPsValueEl.addEventListener("click", () => {
-    copyRdsPsToClipboard();
+    void copyRdsPsToClipboard();
   });
 }
 var rdsRawCopyBtn = document.getElementById("rds-raw-copy-btn");
 if (rdsRawCopyBtn) {
   rdsRawCopyBtn.addEventListener("click", () => {
-    copyRdsRawToClipboard();
+    void copyRdsRawToClipboard();
   });
 }
 var rdsAfListEl = document.getElementById("rds-af-list");
@@ -8202,7 +8256,7 @@ function drawSpectrumWaterfall() {
   const maxDb = minDb + Math.max(20, isFiniteNumber(spectrumRange) ? spectrumRange : 90);
   const view = spectrumVisibleRange(lastSpectrumData);
   const viewKey = `${Math.round(view.visLoHz)}:${Math.round(view.visHiHz)}`;
-  const palKey = `swf|${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
+  const palKey = `swf|${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
   const rowStride = iW * 4;
   const expectedSize = iW * iH * 4;
   const newPushes = spectrumWfPushCount - spectrumWfTexPushCount;
@@ -8329,7 +8383,6 @@ function bmCategoryColorMap() {
 function createBookmarkChip(bm, colorMap, options = {}) {
   const span = document.createElement("span");
   const freqStr = window.trx.modules.bookmarks ? window.trx.modules.bookmarks.formatFrequency(bm.freq_hz) : bm.freq_hz + " Hz";
-  const esc = (s) => String(s).replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
   span.className = "spectrum-bookmark-chip";
   if (options.sideStack) {
     span.classList.add("spectrum-bookmark-chip-side");
@@ -8374,8 +8427,7 @@ function updateBookmarkAxis(range) {
   const leftSideEl = document.getElementById("spectrum-bookmark-side-left");
   const rightSideEl = document.getElementById("spectrum-bookmark-side-right");
   if (!axisEl) return;
-  const _bmRef = window.trx.modules.bookmarks?.overlayList ?? null;
+  const allBookmarks = window.trx.modules.bookmarks?.overlayList ?? [];
-  const allBookmarks = Array.isArray(_bmRef) ? _bmRef : [];
   const visBookmarks = allBookmarks.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz);
   const leftBookmarks = allBookmarks.filter((bm) => bm.freq_hz < range.visLoHz).sort((a, b) => b.freq_hz - a.freq_hz).slice(0, 3);
   const rightBookmarks = allBookmarks.filter((bm) => bm.freq_hz > range.visHiHz).sort((a, b) => a.freq_hz - b.freq_hz).slice(0, 3);
@@ -9106,11 +9158,12 @@ var bandplanStripEl = document.getElementById("spectrum-bandplan-strip");
 var bandplanRegionSelect = document.getElementById("bandplan-region-select");
 var bandplanLabelsCheck = document.getElementById("bandplan-labels-check");
 (function loadBandplanJson() {
-  fetch("/bandplan.json").then((r) => {
+  fetch("/bandplan.json").then(async (response) => {
-    if (!r.ok) throw new Error(String(r.status));
+    if (!response.ok) throw new Error(String(response.status));
-    return r.json();
+    return await responseJsonUnknown(response);
-  }).then((d) => {
+  }).then((data) => {
-    bandplanData = d;
+    if (!isRecord2(data)) return;
+    bandplanData = data;
     bandplanSegmentsCache = null;
     bandplanCacheKey = "";
   }).catch(() => {

src/trx-client/trx-frontend/trx-frontend-http/frontend/eslint.config.js

@@ -36,35 +36,18 @@ export default tseslint.config(
     rules: {
       "no-undef": "off",
       "@typescript-eslint/no-explicit-any": "error",
+      "@typescript-eslint/no-unused-vars": ["error", {
+        argsIgnorePattern: "^_",
+        caughtErrors: "none",
+        varsIgnorePattern: "^_",
+      }],
+      // DOM event targets intentionally ignore listener return values. Async
+      // listeners handle their own failures; keep the rule for all other
+      // promise misuse sites.
+      "@typescript-eslint/no-misused-promises": ["error", { checksVoidReturn: false }],
       "@typescript-eslint/restrict-template-expressions": ["error", { allowNumber: true }],
     },
   },
-  {
-    // app.ts is the final migrated monolith. The compiler checks it with the
-    // full strict baseline; rules that require runtime schemas or broad async
-    // rewrites stay disabled here until those responsibilities are extracted.
-    files: ["src/app.ts"],
-    rules: {
-      "prefer-const": "off",
-      "@typescript-eslint/no-base-to-string": "off",
-      "@typescript-eslint/no-duplicate-type-constituents": "off",
-      "@typescript-eslint/no-floating-promises": "off",
-      "@typescript-eslint/no-misused-promises": "off",
-      "@typescript-eslint/no-unnecessary-condition": "off",
-      "@typescript-eslint/no-unnecessary-type-assertion": "off",
-      "@typescript-eslint/no-unnecessary-type-conversion": "off",
-      "@typescript-eslint/no-unsafe-argument": "off",
-      "@typescript-eslint/no-unsafe-assignment": "off",
-      "@typescript-eslint/no-unsafe-call": "off",
-      "@typescript-eslint/no-unsafe-member-access": "off",
-      "@typescript-eslint/no-unsafe-return": "off",
-      "@typescript-eslint/no-unused-vars": "off",
-      "@typescript-eslint/require-await": "off",
-      "@typescript-eslint/restrict-plus-operands": "off",
-      "@typescript-eslint/restrict-template-expressions": "off",
-      "@typescript-eslint/unbound-method": "off",
-    },
-  },
   {
     files: ["src/decode-history-worker.ts"],
     languageOptions: {

src/trx-client/trx-frontend/trx-frontend-http/frontend/src/app.ts

@@ -44,9 +44,10 @@ import {
 } from "./features/spectrum/math.js";
 import type { NumericBins } from "./features/spectrum/math.js";
 import type { AuthRole } from "./api/auth.js";
-import type { RdsData, RigCapabilities, RigListItem, RigSnapshot } from "./api/generated.js";
+import type { RdsData, RigCapabilities, RigListItem, RigSnapshot, VchanRdsEntry } from "./api/generated.js";
 import type { TrxPluginRuntime } from "./plugins/runtime-contract.js";
 import { loadEagerPlugins, loadPluginsForTab } from "./plugin-loader.js";
+import { isRigListResponse, isRigSnapshot } from "./api/client.js";
 
 interface SpectrumFrame {
   bins: NumericBins;
@@ -224,6 +225,47 @@ interface TrxModules {
   };
   screenshot?: { captureSpectrumScreenshot(): Promise<boolean> };
 }
+interface TrxState {
+  serverLat: number | null;
+  serverLon: number | null;
+  readonly lastFreqHz: number | null;
+  readonly lastActiveRigId: string | null;
+  readonly lastRigIds: string[];
+  readonly lastRigDisplayNames: Record<string, string>;
+  readonly initialMapZoom: number;
+  readonly decodeHistoryRetentionMin: number;
+  readonly authRole: AuthRole | null;
+  readonly decoderRegistry: typeof decoderRegistry;
+  readonly sseSessionId: string | null;
+  readonly primaryRds: RdsData | null;
+  readonly vchanRdsById: Map<string, RdsData | null>;
+  readonly vchanSignalDbById: Map<string, number>;
+  lastCityLabel: string;
+  readonly serverVersion: string | null;
+  readonly serverBuildDate: string | null;
+  readonly serverCallsign: string | null;
+  readonly ownerCallsign: string | null;
+  readonly ownerWebsiteUrl: string | null;
+  readonly ownerWebsiteName: string | null;
+  readonly aisVesselUrlBase: string | null;
+  readonly serverRigs: RigListItem[];
+  readonly serverActiveRigId: string | null;
+  readonly lastModeName: string;
+  readonly lastSpectrumData: SpectrumFrame | null;
+  readonly lastSpectrumRenderData: SpectrumFrame | null;
+  currentBandwidthHz: number;
+  readonly spectrumFloor: number;
+  readonly spectrumRange: number;
+  readonly spectrumCanvas: HTMLCanvasElement;
+  readonly overviewCanvas: HTMLCanvasElement;
+  readonly overviewGl: TrxWebGlRenderer;
+  readonly spectrumGl: TrxWebGlRenderer;
+  readonly signalOverlayGl: TrxWebGlRenderer;
+  readonly decodeHistoryReplayActive: boolean;
+  readonly decodeMapSyncPending: boolean;
+  readonly _activeTab: TabName;
+  readonly locationSubtitle: HTMLElement | null;
+}
 interface TrxUi {
   confirm(options?: { title?: string; message?: string; confirmLabel?: string; danger?: boolean }): Promise<boolean>;
   notify(message: string, options?: { kind?: "info" | "error" | "success" | "warning"; duration?: number; action?: { label?: string; run(): void } | null }): HTMLDivElement;
@@ -250,9 +292,67 @@ function isFiniteNumber(value: unknown): value is number {
   return typeof value === "number" && Number.isFinite(value);
 }
 
+function primitiveString(value: unknown): string {
+  return typeof value === "string" || typeof value === "number" || typeof value === "boolean"
+    ? String(value)
+    : "";
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function parseJsonUnknown(source: string): unknown {
+  return JSON.parse(source) as unknown;
+}
+
+function messageEventData(event: Event): string {
+  const data: unknown = (event as MessageEvent<unknown>).data;
+  if (typeof data !== "string") throw new TypeError("Expected a text event payload");
+  return data;
+}
+
+async function responseJsonUnknown(response: Response): Promise<unknown> {
+  return await response.json() as unknown;
+}
+
+function isAppUpdate(value: unknown): value is AppUpdate {
+  return isRecord(value) && (value.status === undefined || isRecord(value.status));
+}
+
+function isAudioStreamInfo(value: unknown): value is AudioStreamInfo {
+  return isRecord(value)
+    && typeof value.sample_rate === "number"
+    && typeof value.channels === "number";
+}
+
+function isRecorderActiveList(value: unknown): value is RecorderActive[] {
+  return Array.isArray(value) && value.every((entry) => isRecord(entry)
+    && typeof entry.rig_id === "string"
+    && typeof entry.path === "string"
+    && typeof entry.started_at === "number");
+}
+
+function isRecorderFileList(value: unknown): value is RecorderFile[] {
+  return Array.isArray(value) && value.every((entry) => isRecord(entry)
+    && typeof entry.name === "string"
+    && typeof entry.size === "number");
+}
+
+function isRdsData(value: unknown): value is RdsData {
+  return isRecord(value);
+}
+
+function isVchanRdsEntry(value: unknown): value is VchanRdsEntry {
+  return isRecord(value)
+    && typeof value.id === "string"
+    && (value.rds === undefined || value.rds === null || isRdsData(value.rds))
+    && (value.signal_db === undefined || value.signal_db === null || typeof value.signal_db === "number");
+}
+
 declare global {
   interface Window {
-    trx: { state: Record<string, unknown>; core: Record<string, unknown>; modules: TrxModules };
+    trx: { state: TrxState; core: Readonly<Record<string, unknown>>; modules: TrxModules };
     trxUi: TrxUi;
     trxPluginRuntime: TrxPluginRuntime;
     lastSpectrumData: SpectrumFrame | null;
@@ -269,8 +369,6 @@ declare global {
     navigateToTab(name: TabName, options?: { updateHistory?: boolean; replaceHistory?: boolean }): void;
     _syncRecorderState(enabled: boolean): void;
     refreshRdsUi(): void;
-    loadEagerPlugins?(): Promise<void>;
-    loadPluginsForTab?(tab: string): Promise<void>;
     refreshCwTonePicker?(): void;
     updateFt8RfDisplay?(): void;
     clearSatPredictionDom?(): void;
@@ -430,7 +528,6 @@ function applyAuthRestrictions() {
     const txLimitBtn = document.getElementById("tx-limit-btn") as HTMLButtonElement | null;
     const txAudioBtn = document.getElementById("tx-audio-btn") as HTMLButtonElement | null;
     const txLimitRow = document.getElementById("tx-limit-row");
-    const vfoPicker = document.getElementById("vfo-picker");
     const jogUp = document.getElementById("jog-up") as HTMLButtonElement | null;
     const jogDown = document.getElementById("jog-down") as HTMLButtonElement | null;
     const jogButtons = document.querySelectorAll<HTMLButtonElement>(".jog-step button");
@@ -526,7 +623,7 @@ function applyCapabilities(caps: RigCapabilities | null) {
   if (txAudioBtn) txAudioBtn.style.display = caps.tx ? "" : "none";
   if (txVolControl) txVolControl.style.display = caps.tx ? "" : "none";
   if (!caps.tx && typeof stopTxAudio === "function" && txActive) {
-    stopTxAudio();
+    void stopTxAudio();
   }
 
   // TX limit row
@@ -814,11 +911,10 @@ function decodeHistoryMapRenderingDeferred() {
 
 let lastSpectrumData: SpectrumFrame | null = null;
 window.lastSpectrumData = null;
-let lastControl;
 let lastTxEn: boolean | null = null;
 let lastHasTx = true;
 let lastRendered: string | null = null;
-let prevRenderData: Record<string, unknown> = {};
+const prevRenderData: Record<string, unknown> = {};
 let hintTimer: ReturnType<typeof setTimeout> | null = null;
 let sigMeasuring = false;
 let sigLastSUnits: number | null = null;
@@ -941,7 +1037,7 @@ function updateDocumentTitle(rds: RdsData | null = null) {
     document.title = originalTitle;
     return;
   }
-  const parts = [formatFreq(freqHz as number)];
+  const parts = [formatFreq(freqHz)];
   const ps = rds?.program_service;
   if (ps && ps.length > 0) {
     parts.push(ps);
@@ -1327,7 +1423,7 @@ function applyRigList(activeRigId: string | null, rigIds: string[], displayNames
     window.trx.modules.scheduler?.setRig(lastActiveRigId);
     window.trx.modules.backgroundDecode?.setRig(lastActiveRigId);
     window.trx.modules.bookmarks?.populateScopePicker();
-    window.trx.modules.bookmarks?.fetch((document.getElementById("bm-category-filter") as HTMLSelectElement | null)?.value || "");
+    void window.trx.modules.bookmarks?.fetch((document.getElementById("bm-category-filter") as HTMLSelectElement | null)?.value || "");
   }
   window.trx.modules.map?.updateMapRigFilter();
 }
@@ -1337,8 +1433,9 @@ async function refreshRigList() {
   try {
     const resp = await fetch("/rigs", { cache: "no-store" });
     if (!resp.ok) return;
-    const data = await resp.json();
+    const data = await responseJsonUnknown(resp);
-    const rigs = Array.isArray(data.rigs) ? data.rigs : [];
+    if (!isRigListResponse(data)) return;
+    const rigs = data.rigs;
     const rigIds = rigs.map((r: RigListItem) => r.remote).filter(Boolean);
     const displayNames: Record<string, string> = {};
     rigs.forEach((r: RigListItem) => {
@@ -1354,7 +1451,7 @@ async function refreshRigList() {
     });
     serverRigs = rigs;
     refreshOperatorLayoutCapabilities();
-    serverActiveRigId = data.active_remote || null;
+    serverActiveRigId = data.active_remote;
     applyRigList(data.active_remote, rigIds, displayNames);
     window.trx.modules.map?.syncAprsReceiverMarker();
   } catch (e) {
@@ -1399,7 +1496,7 @@ setInterval(() => {
   if (el) el.textContent = formatUptime(Date.now() - aboutUptimeStart);
 }, 1000);
 let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
-let overviewSignalSamples: SignalSample[] = [];
+const overviewSignalSamples: SignalSample[] = [];
 let overviewSignalTimer: ReturnType<typeof setInterval> | null = null;
 let overviewWaterfallRows: NumericBins[] = [];
 let overviewWaterfallPushCount = 0;   // monotonically increments on every push
@@ -1413,8 +1510,9 @@ let overviewWfTexPalKey = "";
 let overviewWfTexReady = false;
 
 function cssColorToRgba(color: string, alphaMul = 1): Rgba {
-  const parser = typeof window.trxParseCssColor === "function" ? window.trxParseCssColor : null;
+  const parsed = typeof window.trxParseCssColor === "function"
-  const parsed = parser ? parser(color) : [0, 0, 0, 1];
+    ? window.trxParseCssColor(color)
+    : [0, 0, 0, 1];
   return [
     parsed[0] ?? 0,
     parsed[1] ?? 0,
@@ -1447,7 +1545,7 @@ function overviewWfResetTextureCache() {
 }
 
 function overviewWfPaletteKey(pal: CanvasPalette, viewKey = "") {
-  return `${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
+  return `${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
 }
 
 function resizeHeaderSignalCanvas() {
@@ -1526,9 +1624,9 @@ function drawSignalOverlay() {
   const bwStroke = BW_OVERLAY_COLORS.stroke;
   const bwHard = BW_OVERLAY_COLORS.hard;
   const bmRef = window.trx.modules.bookmarks?.overlayList ?? null;
-  if (Array.isArray(bmRef) && bmRef.length > 0) {
+  if (bmRef && bmRef.length > 0) {
     const colorMap = bmCategoryColorMap();
-    const grouped = new Map();
+    const grouped = new Map<string, number[]>();
     for (const bm of bmRef) {
       const f = Number(bm?.freq_hz);
       if (!isFiniteNumber(f) || f < range.visLoHz || f > range.visHiHz) continue;
@@ -1536,8 +1634,9 @@ function drawSignalOverlay() {
       const x = hzToX(f);
       if (!isFiniteNumber(x) || x < 0 || x > W) continue;
       const color = colorMap[bm?.category || ""] || BOOKMARK_MARKER_FALLBACK;
-      if (!grouped.has(color)) grouped.set(color, []);
+      const segments = grouped.get(color) ?? [];
-      grouped.get(color).push(x, 0, x, H);
+      segments.push(x, 0, x, H);
+      grouped.set(color, segments);
     }
     for (const [color, segments] of grouped.entries()) {
       if (!Array.isArray(segments) || segments.length === 0) continue;
@@ -1856,7 +1955,7 @@ let _wfLutKey = "";
 const _wfLut = new Uint8Array(256 * 4); // [r,g,b,a] × 256 entries, 0-255 range
 
 function ensureWaterfallLut(pal: CanvasPalette, minDb: number, maxDb: number) {
-  const key = `${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${minDb}|${maxDb}|${waterfallGamma}`;
+  const key = `${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${minDb}|${maxDb}|${waterfallGamma}`;
   if (key === _wfLutKey) return;
   _wfLutKey = key;
   for (let i = 0; i < 256; i++) {
@@ -2000,7 +2099,7 @@ function renderRdsOverlays() {
     el.innerHTML = html;
     el.addEventListener("click", (evt) => {
       evt.stopPropagation();
-      copyRdsPsToClipboard(entry.rds, entry.freq_hz);
+      void copyRdsPsToClipboard(entry.rds, entry.freq_hz);
     });
     el.addEventListener("mouseenter", () => {
       el.style.zIndex = String(entries.length + 10);
@@ -2211,14 +2310,6 @@ function coverageGuardBandwidthHz(mode = modeEl ? modeEl.value : "") {
   return Math.max(0, isFiniteNumber(maxBw) ? maxBw : currentBandwidthHz);
 }
 
-function isAisMode(mode = modeEl ? modeEl.value : "") {
-  return String(mode || "").toUpperCase() === "AIS";
-}
-
-function isVdesMode(mode = modeEl ? modeEl.value : "") {
-  return String(mode || "").toUpperCase() === "VDES";
-}
-
 function visibleBandwidthSpecs(freqHz: number | null = lastFreqHz, mode = modeEl ? modeEl.value : ""): BandwidthSpec[] {
   if (!isFiniteNumber(freqHz)) return [];
   const modeUpper = String(mode || "").toUpperCase();
@@ -2273,10 +2364,6 @@ function coverageSpanForMode(freqHz: number | null, bandwidthHz = coverageGuardB
   return { loHz, hiHz };
 }
 
-function visibleBandwidthCenters(freqHz: number | null = lastFreqHz, mode = modeEl ? modeEl.value : "") {
-  return visibleBandwidthSpecs(freqHz, mode).map((spec) => spec.centerHz);
-}
-
 function effectiveSpectrumCoverageSpanHz(sampleRateHz: number) {
   const sampleRate = Number(sampleRateHz);
   if (!isFiniteNumber(sampleRate) || sampleRate <= 0) return 0;
@@ -2785,7 +2872,7 @@ function updateJogStepSupport(cap: RigCapabilities | null) {
 
 function normalizeMode(modeVal: unknown): string {
   if (typeof modeVal === "string") return modeVal;
-  if (modeVal && typeof modeVal === "object") {
+  if (isRecord(modeVal)) {
     const entries = Object.entries(modeVal);
     if (entries.length > 0) {
       const firstEntry = entries[0];
@@ -3402,7 +3489,7 @@ function render(update: AppUpdate) {
       // When SDR backend is active (spectrum visible), apply BW default for new
       // mode — but only if the server hasn't already pushed a filter_state.
       if (lastSpectrumData && !update.filter) {
-        applyBwDefaultForMode(mode, false);
+        void applyBwDefaultForMode(mode, false);
       }
     }
     updateWfmControls();
@@ -3559,7 +3646,6 @@ function render(update: AppUpdate) {
     powerBtn.setAttribute("aria-pressed", "false");
     powerHint.textContent = "State unknown";
   }
-  lastControl = update.enabled;
 
   if (update.status && update.status.tx && typeof update.status.tx.limit === "number") {
     txLimitInput.value = String(update.status.tx.limit);
@@ -3713,9 +3799,10 @@ async function pollFreshSnapshot() {
       : "/status";
     const resp = await fetch(statusUrl, { cache: "no-store" });
     if (!resp.ok) return;
-    const data = await resp.json();
+    const data = await responseJsonUnknown(resp);
+    if (!isRigSnapshot(data)) return;
     render(data);
-    refreshRigList();
+    void refreshRigList();
     lastEventAt = Date.now();
   } catch (e) {
     // Ignore network errors; connect() retry loop handles reconnection.
@@ -3732,7 +3819,7 @@ function connect() {
   }
   stopMeterStreaming();
   startMeterStreaming();
-  pollFreshSnapshot();
+  void pollFreshSnapshot();
   const eventsUrl = lastActiveRigId
     ? `/events?remote=${encodeURIComponent(lastActiveRigId)}`
     : "/events";
@@ -3743,13 +3830,14 @@ function connect() {
     setConnLostOverlay(false);
     if (tabMainEl) tabMainEl.classList.remove("server-disconnected");
     if (!aboutUptimeStart) aboutUptimeStart = Date.now();
-    pollFreshSnapshot();
+    void pollFreshSnapshot();
-    refreshRigList();
+    void refreshRigList();
   };
-  source.onmessage = (evt) => {
+  source.onmessage = (evt: MessageEvent<string>) => {
     try {
       if (evt.data === lastRendered) return;
-      const data = JSON.parse(evt.data);
+      const data = parseJsonUnknown(evt.data);
+      if (!isAppUpdate(data)) throw new TypeError("Unexpected status event shape");
       lastRendered = evt.data;
       render(data);
       lastEventAt = Date.now();
@@ -3769,13 +3857,14 @@ function connect() {
   });
   source.addEventListener("session", evt => {
     try {
-      const d = JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
-      sseSessionId = d.session_id || null;
+      const d = parseJsonUnknown(eventData);
+      sseSessionId = isRecord(d) && typeof d.session_id === "string" ? d.session_id : null;
     } catch (_) {}
-    window.trx.modules.vchan?.handleSession(evt.data);
+    window.trx.modules.vchan?.handleSession(messageEventData(evt));
   });
   source.addEventListener("channels", evt => {
-    window.trx.modules.vchan?.handleChannels(evt.data);
+    window.trx.modules.vchan?.handleChannels(messageEventData(evt));
   });
   source.onerror = () => {
     // Check if this is an auth error by looking at readyState
@@ -3783,7 +3872,7 @@ function connect() {
       powerHint.textContent = "trx-client connection lost, retrying\u2026";
       setConnLostOverlay(true, "trx-client connection lost", "Retrying\u2026", true);
       source.close();
-      pollFreshSnapshot();
+      void pollFreshSnapshot();
       scheduleReconnect(1000);
     }
   };
@@ -3794,7 +3883,7 @@ function connect() {
       powerHint.textContent = "trx-client connection lost, retrying\u2026";
       setConnLostOverlay(true, "trx-client connection lost", "Retrying\u2026", true);
       source.close();
-      pollFreshSnapshot();
+      void pollFreshSnapshot();
       scheduleReconnect(250);
     }
   }, 5000);
@@ -3827,12 +3916,8 @@ function disconnect() {
 
 // Yield the main thread so the browser can paint before heavy async work.
 // Uses scheduler.yield() (Chrome 115+) with a setTimeout fallback.
-function yieldToMain() {
+const uiFrameJobs = new Map<string, () => void>();
-  return new Promise((resolve) => setTimeout(resolve, 0));
+let uiFrameJobsHandle: ReturnType<typeof setTimeout>   | null = null;
-}
-
-const uiFrameJobs = new Map();
-let uiFrameJobsHandle: ReturnType<typeof setTimeout> | number | null = null;
 
 function flushUiFrameJobs() {
   uiFrameJobsHandle = null;
@@ -3929,7 +4014,7 @@ async function switchRigFromSelect(selectEl: HTMLSelectElement) {
     window.trxUi?.setActiveRig(lastActiveRigId);
     window.trx.modules.scheduler?.setRig(lastActiveRigId);
     window.trx.modules.backgroundDecode?.setRig(lastActiveRigId);
-    window.trx.modules.bookmarks?.fetch((document.getElementById("bm-category-filter") as HTMLSelectElement | null)?.value || "");
+    void window.trx.modules.bookmarks?.fetch((document.getElementById("bm-category-filter") as HTMLSelectElement | null)?.value || "");
     window.trx.modules.map?.syncAprsReceiverMarker();
     connect();
     stopSpectrumStreaming();
@@ -3954,7 +4039,7 @@ async function switchRigFromSelect(selectEl: HTMLSelectElement) {
 }
 
 if (headerRigSwitchSelect) {
-  headerRigSwitchSelect.addEventListener("change", () => { switchRigFromSelect(headerRigSwitchSelect); });
+  headerRigSwitchSelect.addEventListener("change", () => { void switchRigFromSelect(headerRigSwitchSelect); });
 }
 
 function setControlPending(control: HTMLButtonElement | HTMLInputElement | HTMLSelectElement | null, pending: boolean) {
@@ -4057,7 +4142,7 @@ if (centerFreqEl) {
     centerFreqDirty = true;
     if (e.key === "Enter") {
       e.preventDefault();
-      applyCenterFreqFromInput();
+      void applyCenterFreqFromInput();
     } else if (e.key === "Escape") {
       centerFreqDirty = false;
       refreshCenterFreqDisplay();
@@ -4443,15 +4528,15 @@ if (spectrumBwInput) {
   spectrumBwInput.addEventListener("keydown", (e) => {
     if (e.key === "Enter") {
       e.preventDefault();
-      applyBandwidthFromInput();
+      void applyBandwidthFromInput();
     }
   });
 }
 if (spectrumBwSetBtn) {
-  spectrumBwSetBtn.addEventListener("click", () => { applyBandwidthFromInput(); });
+  spectrumBwSetBtn.addEventListener("click", () => { void applyBandwidthFromInput(); });
 }
 if (spectrumBwAutoBtn) {
-  spectrumBwAutoBtn.addEventListener("click", () => { applyAutoBandwidth(); });
+  spectrumBwAutoBtn.addEventListener("click", () => { void applyAutoBandwidth(); });
 }
 if (spectrumBwSweetBtn) {
   spectrumBwSweetBtn.addEventListener("click", () => { applySweetSpotCenter().catch(() => {}); });
@@ -4539,7 +4624,7 @@ function navigateToTab(name: TabName, options: { updateHistory?: boolean; replac
     window.trx.modules.map?.scheduleStatsRender();
   }
   if (name === "recorder") {
-    refreshRecorderStatus();
+    void refreshRecorderStatus();
   }
 }
 window.navigateToTab = navigateToTab;
@@ -4604,10 +4689,6 @@ window.addEventListener("popstate", () => {
 window.addEventListener("resize", () => { scheduleSpectrumLayout(); });
 
 // --- Auth startup sequence ---
-function getAvailableRigIds() {
-  return lastRigIds || [];
-}
-
 async function initializeApp() {
   showAuthGate(false);
   const authStatus = await checkAuthStatus();
@@ -4687,7 +4768,7 @@ requiredElement<HTMLFormElement>("auth-form").addEventListener("submit", async (
 // Setup guest button
 const guestBtn = document.getElementById("auth-guest-btn") as HTMLButtonElement | null;
 if (guestBtn) {
-  guestBtn.addEventListener("click", async () => {
+  guestBtn.addEventListener("click", () => {
     authRole = "rx";
     requiredElement<HTMLInputElement>("auth-passphrase").value = "";
     hideAuthGate();
@@ -4721,12 +4802,12 @@ if (headerAuthBtn) {
 // Modules (map-core.js, screenshot.js) access core state and utilities via
 // window.trx.  Modules register their own APIs as sub-namespaces
 // (e.g. window.trx.modules.map, window.trx.modules.screenshot).
-const trxState = Object.create(null);
+const trxState = Object.create(null) as TrxState;
-const trxModules = Object.create(null);
+const trxModules: TrxModules = {};
 // -- State getters (backed by core-scoped variables) --
 Object.defineProperties(trxState, {
-  serverLat:              { get() { return serverLat;              }, set(v) { serverLat = v; } },
+  serverLat:              { get() { return serverLat;              }, set(v: number | null) { serverLat = v; } },
-  serverLon:              { get() { return serverLon;              }, set(v) { serverLon = v; } },
+  serverLon:              { get() { return serverLon;              }, set(v: number | null) { serverLon = v; } },
   lastFreqHz:             { get() { return lastFreqHz;             } },
   lastActiveRigId:        { get() { return lastActiveRigId;        } },
   lastRigIds:             { get() { return lastRigIds;             } },
@@ -4739,7 +4820,7 @@ Object.defineProperties(trxState, {
   primaryRds:             { get() { return primaryRds;             } },
   vchanRdsById:           { get() { return vchanRdsById;           } },
   vchanSignalDbById:      { get() { return vchanSignalDbById;      } },
-  lastCityLabel:          { get() { return lastCityLabel;          }, set(v) { lastCityLabel = v; } },
+  lastCityLabel:          { get() { return lastCityLabel;          }, set(v: string) { lastCityLabel = v; } },
   serverVersion:          { get() { return serverVersion;          } },
   serverBuildDate:        { get() { return serverBuildDate;        } },
   serverCallsign:         { get() { return serverCallsign;        } },
@@ -4752,7 +4833,7 @@ Object.defineProperties(trxState, {
   lastModeName:           { get() { return lastModeName;          } },
   lastSpectrumData:       { get() { return lastSpectrumData;      } },
   lastSpectrumRenderData: { get() { return lastSpectrumRenderData; } },
-  currentBandwidthHz:     { get() { return currentBandwidthHz;     }, set(v) { currentBandwidthHz = v; window.currentBandwidthHz = v; } },
+  currentBandwidthHz:     { get() { return currentBandwidthHz;     }, set(v: number) { currentBandwidthHz = v; window.currentBandwidthHz = v; } },
   spectrumFloor:          { get() { return spectrumFloor;         } },
   spectrumRange:          { get() { return spectrumRange;         } },
   spectrumCanvas:         { get() { return spectrumCanvas;        } },
@@ -4791,7 +4872,7 @@ window.trx = Object.freeze({ state: trxState, core: trxCore, modules: trxModules
 void loadEagerPlugins().catch((error: unknown) => { console.error(error); });
 
 // Start the app
-initializeApp();
+void initializeApp();
 window.addEventListener("resize", resizeHeaderSignalCanvas);
 
 
@@ -4826,11 +4907,11 @@ function buildBookmarkTooltipText(bm: Bookmark) {
 
 function nearestBookmarkForHz(hz: number, widthPx: number, range: SpectrumRange) {
   const ref = window.trx.modules.bookmarks?.overlayList ?? null;
-  if (!Array.isArray(ref) || !isFiniteNumber(hz) || !widthPx || !range || !isFiniteNumber(range.visSpanHz) || range.visSpanHz <= 0) {
+  if (!ref || !isFiniteNumber(hz) || !widthPx || !range || !isFiniteNumber(range.visSpanHz) || range.visSpanHz <= 0) {
     return null;
   }
   const maxDeltaHz = Math.max((range.visSpanHz / widthPx) * 6, 10);
-  let best = null;
+  let best: Bookmark | null = null;
   let bestDelta = Number.POSITIVE_INFINITY;
   for (const bm of ref) {
     const delta = Math.abs(Number(bm.freq_hz) - hz);
@@ -4961,7 +5042,6 @@ const wfmDeemphasisEl = document.getElementById("wfm-deemphasis") as HTMLSelectE
 const wfmAudioModeEl = document.getElementById("wfm-audio-mode") as HTMLSelectElement | null;
 const wfmDenoiseEl = document.getElementById("wfm-denoise") as HTMLSelectElement | null;
 const sdrSettingsRowEl = document.getElementById("sdr-settings-row");
-const sdrGainControlsEl = document.getElementById("sdr-gain-controls");
 const sdrGainEl = document.getElementById("sdr-gain-db") as HTMLInputElement | null;
 const sdrGainSetBtn = document.getElementById("sdr-gain-set") as HTMLButtonElement | null;
 const sdrLnaGainControlsEl = document.getElementById("sdr-lna-gain-controls");
@@ -5076,7 +5156,7 @@ function levelFromChannels(channels: Float32Array[], frameCount: number) {
 }
 
 function normalizeWfmDenoiseLevel(value: unknown) {
-  const next = String(value ?? "").toLowerCase();
+  const next = primitiveString(value).toLowerCase();
   if (next === "off" || next === "auto" || next === "low" || next === "medium" || next === "high") return next;
   return "auto";
 }
@@ -5306,7 +5386,7 @@ function resetTxTimeout() {
   if (txTimeoutTimer) clearTimeout(txTimeoutTimer);
   txTimeoutTimer = setTimeout(() => {
     console.warn("PTT safety timeout — stopping TX");
-    stopTxAudio();
+    void stopTxAudio();
   }, TX_TIMEOUT_SECS * 1000);
 }
 
@@ -5388,7 +5468,7 @@ function extractAudioFrameChannels(frame: AudioData) {
 }
 
 // Optional channel_id injected by vchan.js when connecting to a virtual channel.
-let _audioChannelOverride: string | null = null;
+const _audioChannelOverride: string | null = null;
 
 /** Schedule decoded PCM channels for playback via Web Audio API. */
 function scheduleDecodedAudio(channelData: Float32Array[], frameCount: number, sampleRate: number) {
@@ -5470,7 +5550,9 @@ function startRxAudio() {
     if (typeof evt.data === "string") {
       // Stream info JSON
       try {
-        configureRxStream(JSON.parse(evt.data));
+        const info = parseJsonUnknown(evt.data);
+        if (!isAudioStreamInfo(info)) throw new TypeError("Unexpected audio stream metadata");
+        configureRxStream(info);
       } catch (e) {
         console.error("Audio stream info parse error", e);
       }
@@ -5543,7 +5625,7 @@ function startRxAudio() {
       } catch (e) { /* ignore per-frame errors */ }
     } else if (wasmOpusDecoder) {
       try {
-        const result = wasmOpusDecoder.decodeFrame(data);
+        const result = wasmOpusDecoder.decodeFrame(data as Uint8Array<ArrayBufferLike>);
         if (result && result.samplesDecoded > 0) {
           scheduleDecodedAudio(result.channelData, result.samplesDecoded, result.sampleRate ?? streamInfo?.sample_rate ?? 48000);
         }
@@ -5553,7 +5635,7 @@ function startRxAudio() {
 
   audioWs.onclose = () => {
     // If TX was active when WS closed, release PTT
-    if (txActive) { stopTxAudio(); }
+    if (txActive) { void stopTxAudio(); }
     rxActive = false;
     window.trxUi?.setButtonState(rxAudioBtn, { active: false, activeLabel: "Stop Audio", inactiveLabel: "Play Audio" });
     streamInfo = null;
@@ -5585,7 +5667,7 @@ function stopRxAudio() {
   window.trxUi?.setButtonState(rxAudioBtn, { active: false, activeLabel: "Stop Audio", inactiveLabel: "Play Audio" });
   streamInfo = null;
   if (audioWs) { audioWs.close(); audioWs = null; }
-  if (audioCtx) { audioCtx.close(); audioCtx = null; }
+  if (audioCtx) { void audioCtx.close(); audioCtx = null; }
   updateWfmControls();
   rxGainNode = null;
   if (opusDecoder) {
@@ -5605,7 +5687,7 @@ function stopRxAudio() {
 }
 
 function startTxAudio() {
-  if (txActive) { stopTxAudio(); return; }
+  if (txActive) { void stopTxAudio(); return; }
   if (!hasWebCodecs) {
     audioStatus.textContent = "Audio requires Chrome/Edge";
     return;
@@ -5796,12 +5878,15 @@ async function refreshRecorderStatus() {
       fetch("/api/recorder/files"),
     ]);
     if (statusResp.ok) {
-      const active = await statusResp.json();
+      const active = await responseJsonUnknown(statusResp);
-      renderRecorderActive(active);
+      if (isRecorderActiveList(active)) renderRecorderActive(active);
     }
     if (filesResp.ok) {
-      _recorderFiles = await filesResp.json();
+      const files = await responseJsonUnknown(filesResp);
-      renderRecorderFiles();
+      if (isRecorderFileList(files)) {
+        _recorderFiles = files;
+        renderRecorderFiles();
+      }
     }
   } catch (e) {
     console.error("Recorder status fetch failed", e);
@@ -5933,7 +6018,7 @@ function renderRecorderFiles() {
       row.parentNode?.insertBefore(playerRow, row.nextSibling);
       btn.setAttribute("aria-expanded", "true");
       btn.textContent = "Hide";
-      try { audio.play(); } catch (_) {}
+      void audio.play().catch(() => {});
     });
   });
 
@@ -6009,7 +6094,6 @@ requiredElement("copyright-year").textContent = String(new Date().getFullYear())
 
 // --- Server-side decode SSE ---
 let decodeSource: EventSource | null = null;
-let decodeConnected = false;
 let decodeHistoryWorker: Worker | null = null;
 function setModeBoundDecodeStatus(el: HTMLElement | null, activeModes: string[], inactiveText: string, connectedText: string) {
   if (!el) return;
@@ -6047,27 +6131,6 @@ function dispatchDecodeMessage(msg: DecodeMessage, skipStats = false) {
   }
 }
 
-function dispatchDecodeBatch(batch: DecodeMessage[]) {
-  if (!Array.isArray(batch) || batch.length === 0) return;
-  // Record statistics for every message in the batch regardless of dispatch path.
-  for (const msg of batch) {
-    if (msg.type && msg.type !== "lrpt_image" && msg.type !== "lrpt_progress" && msg.type !== "wefax" && msg.type !== "wefax_progress") {
-      window.trx.modules.map?.statsRecordDecode(msg.type, msg.rig_id || msg.remote || null);
-    }
-  }
-  window.trx.modules.map?.scheduleStatsRender();
-  const type = String(batch[0]?.type || "");
-  const uniformType = batch.every((msg) => String(msg?.type || "") === type);
-  if (uniformType && type) {
-    window.trxPluginRuntime.dispatchBatch(type, batch);
-    return;
-  }
-  for (const msg of batch) {
-    dispatchDecodeMessage(msg, true);
-  }
-}
-
-const DECODE_HISTORY_TYPE_BATCH_LIMIT = 192;
 const DECODE_HISTORY_WORKER_GROUP_LIMIT = 512;
 const DECODE_HISTORY_BATCH_DRAIN_BUDGET_MS = 8;
 
@@ -6249,11 +6312,12 @@ function connectDecode() {
       return false;
     }
     decodeHistoryWorker = worker;
-    worker.onmessage = (evt) => {
+    worker.onmessage = (evt: MessageEvent<unknown>) => {
       if (historySettled || worker !== decodeHistoryWorker) return;
-      const data = evt?.data || {};
+      const data = evt.data;
+      if (!isRecord(data) || typeof data.type !== "string") return;
       if (data.type === "status") {
-        const phase = String(data.phase || "");
+        const phase = primitiveString(data.phase);
         if (phase === "fetching") {
           setDecodeHistoryOverlayVisible(true, "Loading decode history…", "Fetching recent decodes from the client buffer");
         } else if (phase === "decoding") {
@@ -6271,7 +6335,10 @@ function connectDecode() {
         return;
       }
       if (data.type === "group") {
-        enqueueDecodeHistoryGroup(String(data.kind || ""), data.messages);
+        const messages = Array.isArray(data.messages)
+          ? data.messages.filter((message): message is DecodeMessage => isRecord(message) && typeof message.type === "string")
+          : [];
+        enqueueDecodeHistoryGroup(typeof data.kind === "string" ? data.kind : "", messages);
         return;
       }
       if (data.type === "done") {
@@ -6282,7 +6349,7 @@ function connectDecode() {
         return;
       }
       if (data.type === "error") {
-        console.error("Decode history worker failed", data.message || "unknown worker failure");
+        console.error("Decode history worker failed", typeof data.message === "string" ? data.message : "unknown worker failure");
         terminateDecodeHistoryWorker();
         startDecodeHistoryFallback();
       }
@@ -6307,21 +6374,21 @@ function connectDecode() {
   decodeSource = new EventSource("/decode");
   const source = decodeSource;
   source.onopen = () => {
-    decodeConnected = true;
     updateDecodeStatus("Connected, listening for packets");
   };
-  source.onmessage = (evt) => {
+  source.onmessage = (evt: MessageEvent<string>) => {
     try {
-      const msg = JSON.parse(evt.data);
+      const msg = parseJsonUnknown(evt.data);
-      if (historySettled) dispatchDecodeMessage(msg);
+      if (!isRecord(msg) || typeof msg.type !== "string") return;
-      else liveBuffer.push(msg);
+      const decoded: DecodeMessage = { ...msg, type: msg.type };
+      if (historySettled) dispatchDecodeMessage(decoded);
+      else liveBuffer.push(decoded);
     } catch (e) { /* ignore parse errors */ }
   };
   source.onerror = () => {
     // readyState CLOSED (2) = server rejected (404/error), CONNECTING (0) = temporary drop
     const wasClosed = source.readyState === 2;
     source.close();
-    decodeConnected = false;
     terminateDecodeHistoryWorker();
     if (!historySettled) flushLiveBuffer();
     if (wasClosed) {
@@ -6385,7 +6452,7 @@ let spectrumRange = 90;
 let waterfallGamma = 1.0;
 const SPECTRUM_HEADROOM_DB = 20;
 const SPECTRUM_SMOOTH_ALPHA = 0.42;
-let _spectrumBinBuf = []; // Reusable buffer for SSE bin decoding
+const _spectrumBinBuf = []; // Reusable buffer for SSE bin decoding
 // Crosshair state (CSS coords relative to spectrum canvas).
 let spectrumCrosshairX: number | null = null;
 let spectrumCrosshairY: number | null = null;
@@ -6534,7 +6601,7 @@ function buildSpectrumRenderData(frame: SpectrumFrame): SpectrumFrame {
     prev.bins.length === n &&
     prev.sample_rate === frame.sample_rate &&
     prev.center_hz === frame.center_hz;
-  if (_smoothBins.length !== n) _smoothBins = new Array(n);
+  if (_smoothBins.length !== n) _smoothBins = new Array<number>(n);
   const src = frame.bins;
   if (canBlend) {
     const prevBins = prev.bins;
@@ -6730,11 +6797,12 @@ function startSpectrumStreaming() {
   // Bins are i8 (1 dB/step), base64-encoded for ~5× size reduction vs JSON f32 array.
   source.addEventListener("b", (evt) => {
     try {
-      const commaA = evt.data.indexOf(",");
+      const eventData = messageEventData(evt);
-      const commaB = evt.data.indexOf(",", commaA + 1);
+      const commaA = eventData.indexOf(",");
-      const centerHz = Number(evt.data.slice(0, commaA));
+      const commaB = eventData.indexOf(",", commaA + 1);
-      const sampleRate = Number(evt.data.slice(commaA + 1, commaB));
+      const centerHz = Number(eventData.slice(0, commaA));
-      const b64 = evt.data.slice(commaB + 1);
+      const sampleRate = Number(eventData.slice(commaA + 1, commaB));
+      const b64 = eventData.slice(commaB + 1);
       const hadSpectrum = !!lastSpectrumData;
       const bins = decodeBase64ToInt8(b64);
       // Preserve any RDS data from the last rds event.
@@ -6772,29 +6840,29 @@ function startSpectrumStreaming() {
   // Named "rds" event = RDS metadata changed (emitted only when it changes).
   source.addEventListener("rds", (evt) => {
     try {
-      const rds = evt.data === "null" ? undefined : JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
+      const value = eventData === "null" ? undefined : parseJsonUnknown(eventData);
+      const rds = value !== undefined && isRdsData(value) ? value : null;
       if (lastSpectrumData) lastSpectrumData.rds = rds;
       updateRdsPsOverlay(rds ?? null);
     } catch (_) {}
   });
   source.addEventListener("rds_vchan", (evt) => {
     try {
-      const payload = evt.data === "null" ? [] : JSON.parse(evt.data);
+      const eventData = messageEventData(evt);
-      const next = new Map();
+      const value = eventData === "null" ? [] : parseJsonUnknown(eventData);
-      const nextSig = new Map();
+      const payload = Array.isArray(value) ? value.filter(isVchanRdsEntry) : [];
-      if (Array.isArray(payload)) {
+      const next = new Map<string, RdsData | null>();
-        payload.forEach((entry) => {
+      const nextSig = new Map<string, number>();
-          if (entry && entry.id) {
+      payload.forEach((entry) => {
-            next.set(entry.id, entry.rds ?? null);
+        next.set(entry.id, entry.rds ?? null);
-            if (typeof entry.signal_db === "number") nextSig.set(entry.id, entry.signal_db);
+        if (typeof entry.signal_db === "number") nextSig.set(entry.id, entry.signal_db);
-          }
+      });
-        });
-      }
       vchanRdsById = next;
       vchanSignalDbById = nextSig;
       const virtualChannelId = window.trx.modules.vchan?.activeId;
       if (virtualChannelId && nextSig.has(virtualChannelId)) {
-        sigLastDbm = nextSig.get(virtualChannelId);
+        sigLastDbm = nextSig.get(virtualChannelId) ?? null;
         refreshSigStrengthDisplay();
       }
       updateRdsPsOverlay(primaryRds);
@@ -6893,10 +6961,10 @@ function startMeterStreaming() {
     ? `/meter?remote=${encodeURIComponent(lastActiveRigId)}`
     : "/meter";
   meterSource = new EventSource(url);
-  meterSource.onmessage = (evt) => {
+  meterSource.onmessage = (evt: MessageEvent<string>) => {
     try {
-      const { sig } = JSON.parse(evt.data);
+      const value = parseJsonUnknown(evt.data);
-      applyMeterSample(sig);
+      if (isRecord(value) && typeof value.sig === "number") applyMeterSample(value.sig);
     } catch (_) {}
   };
   meterSource.onerror = () => {
@@ -6934,14 +7002,14 @@ function clearSpectrumCanvas() {
 }
 
 function formatOverlayPs(ps: unknown) {
-  return String(ps ?? "")
+  return primitiveString(ps)
     .slice(0, 8)
     .padEnd(8, "_")
     .replaceAll(" ", "_");
 }
 
 function formatPsHtml(ps: unknown) {
-  const clipped = String(ps ?? "").slice(0, 8);
+  const clipped = primitiveString(ps).slice(0, 8);
   let html = "";
   for (let i = 0; i < 8; i += 1) {
     const ch = clipped[i];
@@ -6961,8 +7029,10 @@ function formatOverlayPi(pi: unknown) {
 }
 
 function formatOverlayPty(pty: unknown, ptyName: unknown) {
-  if (ptyName) return ptyName;
+  const name = primitiveString(ptyName);
-  return pty != null ? String(pty) : "--";
+  if (name) return name;
+  const code = primitiveString(pty);
+  return code || "--";
 }
 
 function overlayTrafficFlagHtml(label: string, active: boolean | null | undefined) {
@@ -7077,11 +7147,11 @@ async function copyRdsRawToClipboard() {
 
 const rdsPsValueEl = document.getElementById("rds-ps");
 if (rdsPsValueEl) {
-  rdsPsValueEl.addEventListener("click", () => { copyRdsPsToClipboard(); });
+  rdsPsValueEl.addEventListener("click", () => { void copyRdsPsToClipboard(); });
 }
 const rdsRawCopyBtn = document.getElementById("rds-raw-copy-btn") as HTMLButtonElement | null;
 if (rdsRawCopyBtn) {
-  rdsRawCopyBtn.addEventListener("click", () => { copyRdsRawToClipboard(); });
+  rdsRawCopyBtn.addEventListener("click", () => { void copyRdsRawToClipboard(); });
 }
 const rdsAfListEl = document.getElementById("rds-af-list");
 if (rdsAfListEl) {
@@ -7408,7 +7478,7 @@ function drawSpectrumWaterfall() {
   const maxDb = minDb + Math.max(20, isFiniteNumber(spectrumRange) ? spectrumRange : 90);
   const view = spectrumVisibleRange(lastSpectrumData);
   const viewKey = `${Math.round(view.visLoHz)}:${Math.round(view.visHiHz)}`;
-  const palKey = `swf|${pal.waterfallHue}|${pal.waterfallSat}|${pal.waterfallLight}|${pal.waterfallAlpha}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
+  const palKey = `swf|${pal.waterfallHue.join(",")}|${pal.waterfallSat}|${pal.waterfallLight.join(",")}|${pal.waterfallAlpha.join(",")}|${spectrumFloor}|${spectrumRange}|${waterfallGamma}|${viewKey}`;
   const rowStride = iW * 4;
   const expectedSize = iW * iH * 4;
   const newPushes = spectrumWfPushCount - spectrumWfTexPushCount;
@@ -7475,13 +7545,6 @@ function drawSpectrumWaterfall() {
   spectrumWaterfallGl.drawTexture("spectrum-waterfall", 0, 0, W, H, 1, true);
 }
 
-function bmHexToRgba(hex: string, alpha: number) {
-  const r = parseInt(hex.slice(1, 3), 16);
-  const g = parseInt(hex.slice(3, 5), 16);
-  const b = parseInt(hex.slice(5, 7), 16);
-  return `rgba(${r},${g},${b},${alpha})`;
-}
-
 // WCAG relative luminance; threshold 0.4 splits well across the palette.
 function bmLuminance(hex: string) {
   const lin = (c: number) => c <= 0.03928 ? c / 12.92 : Math.pow((c + 0.055) / 1.055, 2.4);
@@ -7559,8 +7622,6 @@ function createBookmarkChip(bm: Bookmark, colorMap: Record<string, string>, opti
   const span = document.createElement("span");
   const freqStr = window.trx.modules.bookmarks
     ? window.trx.modules.bookmarks.formatFrequency(bm.freq_hz) : bm.freq_hz + "\u202fHz";
-  const esc = (s: unknown) => String(s)
-    .replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
   span.className = "spectrum-bookmark-chip";
   if (options.sideStack) {
     span.classList.add("spectrum-bookmark-chip-side");
@@ -7626,8 +7687,7 @@ function updateBookmarkAxis(range: SpectrumRange) {
   const rightSideEl = document.getElementById("spectrum-bookmark-side-right");
   if (!axisEl) return;
 
-  const _bmRef = window.trx.modules.bookmarks?.overlayList ?? null;
+  const allBookmarks = window.trx.modules.bookmarks?.overlayList ?? [];
-  const allBookmarks = Array.isArray(_bmRef) ? _bmRef : [];
   const visBookmarks = allBookmarks.filter((bm) => bm.freq_hz >= range.visLoHz && bm.freq_hz <= range.visHiHz);
   const leftBookmarks = allBookmarks
     .filter((bm) => bm.freq_hz < range.visLoHz)
@@ -8439,8 +8499,16 @@ const bandplanLabelsCheck = document.getElementById("bandplan-labels-check") as
 
 (function loadBandplanJson() {
   fetch("/bandplan.json")
-    .then((r) => { if (!r.ok) throw new Error(String(r.status)); return r.json(); })
+    .then(async (response) => {
-    .then((d) => { bandplanData = d; bandplanSegmentsCache = null; bandplanCacheKey = ""; })
+      if (!response.ok) throw new Error(String(response.status));
+      return await responseJsonUnknown(response);
+    })
+    .then((data) => {
+      if (!isRecord(data)) return;
+      bandplanData = data as BandplanData;
+      bandplanSegmentsCache = null;
+      bandplanCacheKey = "";
+    })
     .catch(() => {});
 })();