[refactor](trx-frontend-*): update frontend implementations for context parameter

Update all three built-in frontends to accept Arc<FrontendRuntimeContext>
parameter in their spawn_frontend implementations:

- trx-frontend-http: passes context to serve function
- trx-frontend-http-json: passes context to serve function
- trx-frontend-rigctl: accepts context (minimal impact, no globals used)

Frontends are now ready to use context for audio channels, decode
channels, and auth tokens instead of accessing globals directly.

This completes the trait signature change for all frontends.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-client/trx-frontend/trx-frontend-http-json/src/server.rs

@@ -73,16 +73,21 @@ impl FrontendSpawner for HttpJsonFrontend {
         rig_tx: mpsc::Sender<RigRequest>,
         _callsign: Option<String>,
         listen_addr: SocketAddr,
+        context: std::sync::Arc<trx_frontend::FrontendRuntimeContext>,
     ) -> JoinHandle<()> {
         tokio::spawn(async move {
-            if let Err(e) = serve(listen_addr, rig_tx).await {
+            if let Err(e) = serve(listen_addr, rig_tx, context).await {
                 error!("json tcp server error: {:?}", e);
             }
         })
     }
 }
 
-async fn serve(listen_addr: SocketAddr, rig_tx: mpsc::Sender<RigRequest>) -> std::io::Result<()> {
+async fn serve(
+    listen_addr: SocketAddr,
+    rig_tx: mpsc::Sender<RigRequest>,
+    _context: std::sync::Arc<trx_frontend::FrontendRuntimeContext>,
+) -> std::io::Result<()> {
     let listener = TcpListener::bind(listen_addr).await?;
     info!("json tcp frontend listening on {}", listen_addr);