[feat](trx-frontend-http): wire HF APRS toggle button and bookmark decoder

- Add "Enable HF APRS" toggle button to the HF APRS tab (same style as
  FT8/WSPR); button is disabled during TX like other decoder toggles
- app.js: sync button text/colour from SSE state updates
- hf-aprs.js: connect button click to /toggle_hf_aprs_decode
- bookmarks.js: add "HF APRS" checkbox to Add/Edit Bookmark decoder
  section; bmReadDecoders/bmWriteDecoders handle "hf-aprs" key; bmApply
  toggles the decoder to match bookmark preference on recall

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

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

@@ -222,6 +222,7 @@ function applyAuthRestrictions() {
       "vdes-clear-btn",
       "ft8-decode-toggle-btn",
       "wspr-decode-toggle-btn",
+      "hf-aprs-decode-toggle-btn",
       "cw-auto",
       "aprs-clear-btn",
       "ft8-clear-btn",
@@ -2476,6 +2477,13 @@ function render(update) {
     wsprToggleBtn.style.borderColor = wsprOn ? "#00d17f" : "";
     wsprToggleBtn.style.color = wsprOn ? "#00d17f" : "";
   }
+  const hfAprsToggleBtn = document.getElementById("hf-aprs-decode-toggle-btn");
+  if (hfAprsToggleBtn) {
+    const hfAprsOn = !!update.hf_aprs_decode_enabled;
+    hfAprsToggleBtn.textContent = hfAprsOn ? "Disable HF APRS" : "Enable HF APRS";
+    hfAprsToggleBtn.style.borderColor = hfAprsOn ? "#00d17f" : "";
+    hfAprsToggleBtn.style.color = hfAprsOn ? "#00d17f" : "";
+  }
   const cwAutoEl = document.getElementById("cw-auto");
   const cwWpmEl = document.getElementById("cw-wpm");
   const cwToneEl = document.getElementById("cw-tone");