[feat](trx-frontend-http): add dedicated WSPR plugin tab

Expose a WSPR subtab in the Plugins view with its own controls and
message list, wire a dedicated wspr.js asset endpoint, and route WSPR
decode events to the new panel.

This makes WSPR visible in the HTTP frontend instead of reusing the
FT8 panel for WSPR messages.

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-client/trx-frontend/trx-frontend-http/assets/web/plugins/ft8.js

@@ -149,15 +149,3 @@ window.onServerFt8 = function(msg) {
     message: msg.message,
   });
 };
-
-// Reuse FT8 table rendering for WSPR until a dedicated WSPR panel is added.
-window.onServerWspr = function(msg) {
-  ft8Status.textContent = "Receiving";
-  addFt8Message({
-    ts_ms: msg.ts_ms,
-    snr_db: msg.snr_db,
-    dt_s: msg.dt_s,
-    freq_hz: msg.freq_hz,
-    message: `[WSPR] ${msg.message}`,
-  });
-};