[fix](trx-rs): fix LRPT pass detection status never updating during active decoding

The #sat-status element was stuck on "Waiting for satellite pass" because:

1. The client audio handler (audio_client.rs) did not include AUDIO_MSG_LRPT_IMAGE
   in its message type match, so LRPT image messages from the server were silently
   dropped and never reached the frontend.

2. No progress was reported during active LRPT decoding — the only status update
   happened when a complete image was finalized, which could take the entire pass.

3. The sat-status text was never updated when the decoder was enabled/disabled,
   leaving it permanently at the HTML default text.

Changes:
- Add DecodedMessage::LrptProgress variant for live MCU progress reporting
- Send LRPT progress updates from the decoder task when new MCUs are decoded
- Add AUDIO_MSG_LRPT_IMAGE and AUDIO_MSG_LRPT_PROGRESS to client audio handler
- Update sat-status text when decoder state changes (enabled/disabled)
- Handle lrpt_progress messages in the frontend to show "Receiving — N MCU rows"

https://claude.ai/code/session_017knbD7dr6hJGAWR6pModL7
Signed-off-by: Claude <noreply@anthropic.com>

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

@@ -9134,7 +9134,8 @@ function dispatchDecodeMessage(msg, skipStats) {
   if (msg.type === "ft2" && window.onServerFt2) window.onServerFt2(msg);
   if (msg.type === "wspr" && window.onServerWspr) window.onServerWspr(msg);
   if (msg.type === "lrpt_image" && window.onServerLrptImage) window.onServerLrptImage(msg);
-  if (!skipStats && msg.type && msg.type !== "lrpt_image") {
+  if (msg.type === "lrpt_progress" && window.onServerLrptProgress) window.onServerLrptProgress(msg);
+  if (!skipStats && msg.type && msg.type !== "lrpt_image" && msg.type !== "lrpt_progress") {
     statsRecordDecode(msg.type, msg.rig_id || msg.remote || null);
     scheduleStatsRender();
   }
@@ -9144,7 +9145,7 @@ function dispatchDecodeBatch(batch) {
   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") {
+    if (msg.type && msg.type !== "lrpt_image" && msg.type !== "lrpt_progress") {
       statsRecordDecode(msg.type, msg.rig_id || msg.remote || null);
     }
   }
@@ -9231,7 +9232,7 @@ function loadDecodeHistoryOnMainThread(onReady, onError) {
 function restoreDecodeHistoryGroup(kind, messages) {
   if (!Array.isArray(messages) || messages.length === 0) return;
   // Record statistics for restored history messages.
-  if (kind !== "lrpt_image") {
+  if (kind !== "lrpt_image" && kind !== "lrpt_progress") {
     for (const msg of messages) {
       statsRecordDecode(kind, msg.rig_id || msg.remote || null, msg.ts_ms || undefined);
     }