[feat](trx-frontend-http): draw APRS symbols from the sprite sheets

Resolve a table/code pair to a sprite cell in aprs-shared, and use it
from both the packet lists and the map markers, which had each been
printing the raw symbol character in a bordered box.

A table identifier of / or \ selects the primary or alternate sheet
directly.  Anything else is an overlay character, which the APRS spec
draws on top of the alternate symbol -- so those stack the overlay sheet
over the alternate one rather than picking a sheet.  Codes outside
0x21..0x7E have no cell and keep the old character box.

The sheet URLs stay in the stylesheet so a min-resolution query can swap
in the retina sheets; only the cell offset is computed and set inline.
Map markers share the helper through the plugin chunk, so the map stays
free of any remote symbol fetch.

Verified in a browser against the real stylesheet and sheets: /> is a
car, /_ a WX circle, /& an igate diamond, \n a red triangle, and the
overlays S> and 7# carry their character on the alternate symbol.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018huL1ELyr86yVqfAabtioA
Signed-off-by: Stan Grams <sjg@haxx.space>

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

@@ -0,0 +1,156 @@
+// src/plugins/aprs-shared.ts
+function aprsPacketCategory(packet) {
+  const type = (packet.type ?? "").toLowerCase();
+  const info = (packet.info ?? "").toLowerCase();
+  if (packet.lat != null && packet.lon != null || type.includes("position")) return "position";
+  if (type.includes("message") || info.startsWith(":")) return "message";
+  if (type.includes("weather") || info.startsWith("_")) return "weather";
+  if (type.includes("telemetry") || info.startsWith("t#")) return "telemetry";
+  return "other";
+}
+function aprsCategoryLabel(category) {
+  switch (category) {
+    case "position":
+      return "Position";
+    case "message":
+      return "Message";
+    case "weather":
+      return "Weather";
+    case "telemetry":
+      return "Telemetry";
+    default:
+      return "Other";
+  }
+}
+function aprsAgeText(timestampMs) {
+  if (typeof timestampMs !== "number" || !Number.isFinite(timestampMs)) return "just now";
+  const seconds = Math.round(Math.max(0, Date.now() - timestampMs) / 1e3);
+  if (seconds < 5) return "just now";
+  if (seconds < 60) return `${String(seconds)}s ago`;
+  const minutes = Math.round(seconds / 60);
+  if (minutes < 60) return `${String(minutes)}m ago`;
+  return `${String(Math.round(minutes / 60))}h ago`;
+}
+function aprsPacketSignature(packet) {
+  return [
+    packet.srcCall ?? "",
+    packet.destCall ?? "",
+    packet.path ?? "",
+    packet.info ?? "",
+    packet.type ?? "",
+    packet.lat?.toFixed(4) ?? "",
+    packet.lon?.toFixed(4) ?? ""
+  ].join("|");
+}
+function collapseAprsDuplicates(packets) {
+  const seen = /* @__PURE__ */ new Set();
+  return packets.filter((packet) => {
+    const signature = aprsPacketSignature(packet);
+    if (seen.has(signature)) return false;
+    seen.add(signature);
+    return true;
+  });
+}
+function aprsHexBytes(bytes) {
+  if (!bytes?.length) return "--";
+  return bytes.map((byte) => byte.toString(16).toUpperCase().padStart(2, "0")).join(" ");
+}
+function renderAprsInfo(packet) {
+  if (packet.info_bytes?.length) {
+    return packet.info_bytes.map((byte) => renderAprsByte(byte)).join("");
+  }
+  return Array.from(packet.info ?? "", (character) => renderAprsCharacter(character)).join("");
+}
+function renderAprsByte(byte) {
+  return byte >= 32 && byte <= 126 ? escapeAprsCharacter(String.fromCharCode(byte)) : `<span class="aprs-byte">0x${byte.toString(16).toUpperCase().padStart(2, "0")}</span>`;
+}
+function renderAprsCharacter(character) {
+  const code = character.charCodeAt(0);
+  return code >= 32 && code <= 126 ? escapeAprsCharacter(character) : `<span class="aprs-byte">0x${code.toString(16).toUpperCase().padStart(2, "0")}</span>`;
+}
+function escapeAprsCharacter(character) {
+  if (character === "<") return "&lt;";
+  if (character === ">") return "&gt;";
+  if (character === "&") return "&amp;";
+  if (character === '"') return "&quot;";
+  return character;
+}
+var APRS_SPRITE_COLUMNS = 16;
+var APRS_SPRITE_CELL_PX = 24;
+var APRS_SPRITE_FIRST_CODE = 33;
+var APRS_SPRITE_LAST_CODE = 126;
+function aprsSpriteOffset(code) {
+  if (code.length !== 1) return null;
+  const point = code.charCodeAt(0);
+  if (point < APRS_SPRITE_FIRST_CODE || point > APRS_SPRITE_LAST_CODE) return null;
+  const index = point - APRS_SPRITE_FIRST_CODE;
+  const column = index % APRS_SPRITE_COLUMNS;
+  const row = Math.floor(index / APRS_SPRITE_COLUMNS);
+  return `${String(-column * APRS_SPRITE_CELL_PX)}px ${String(-row * APRS_SPRITE_CELL_PX)}px`;
+}
+function aprsSymbolSprite(symbolTable, symbolCode) {
+  if (!symbolTable || !symbolCode) return null;
+  const symbolOffset = aprsSpriteOffset(symbolCode);
+  if (!symbolOffset) return null;
+  if (symbolTable === "/") {
+    return {
+      className: "aprs-symbol-primary",
+      backgroundPosition: symbolOffset,
+      label: `Primary APRS symbol ${symbolTable}${symbolCode}`
+    };
+  }
+  if (symbolTable === "\\") {
+    return {
+      className: "aprs-symbol-alternate",
+      backgroundPosition: symbolOffset,
+      label: `Alternate APRS symbol ${symbolTable}${symbolCode}`
+    };
+  }
+  const overlayOffset = aprsSpriteOffset(symbolTable);
+  if (!overlayOffset) return null;
+  return {
+    className: "aprs-symbol-overlaid",
+    backgroundPosition: `${overlayOffset}, ${symbolOffset}`,
+    label: `Alternate APRS symbol \\${symbolCode} with overlay ${symbolTable}`
+  };
+}
+function renderLocalAprsSymbol(packet, escapeHtml) {
+  if (!packet.symbolTable || !packet.symbolCode) return "";
+  const sprite = aprsSymbolSprite(packet.symbolTable, packet.symbolCode);
+  if (sprite) {
+    return `<span class="aprs-symbol ${sprite.className}" role="img" style="background-position:${sprite.backgroundPosition}" title="${escapeHtml(sprite.label)}" aria-label="${escapeHtml(sprite.label)}"></span>`;
+  }
+  const symbol = escapeHtml(packet.symbolCode);
+  const table = packet.symbolTable === "/" ? "Primary" : "Alternate";
+  return `<span class="aprs-symbol aprs-symbol-local" title="${table} APRS symbol ${symbol}">${symbol}</span>`;
+}
+function normalizeAprsPacket(packet, receiver) {
+  return {
+    rig_id: packet.rig_id || null,
+    receiver,
+    srcCall: packet.src_call ?? "",
+    destCall: packet.dest_call ?? "",
+    path: packet.path ?? "",
+    info: packet.info ?? "",
+    info_bytes: packet.info_bytes ?? [],
+    type: packet.packet_type ?? "",
+    crcOk: packet.crc_ok ?? false,
+    ts_ms: packet.ts_ms ?? null,
+    lat: packet.lat ?? null,
+    lon: packet.lon ?? null,
+    symbolTable: packet.symbol_table ?? null,
+    symbolCode: packet.symbol_code ?? null
+  };
+}
+
+export {
+  aprsPacketCategory,
+  aprsCategoryLabel,
+  aprsAgeText,
+  collapseAprsDuplicates,
+  aprsHexBytes,
+  renderAprsInfo,
+  aprsSymbolSprite,
+  renderLocalAprsSymbol,
+  normalizeAprsPacket
+};