[refactor](trx-client): create and thread FrontendRuntimeContext through bootstrap

Create FrontendRuntimeContext as Arc during async_init and pass it to all
spawn_frontend calls, enabling explicit context-based initialization.

Changes:
- Create frontend_runtime_ctx as Arc<FrontendRuntimeContext>
- Pass context to all spawn_frontend invocations in the frontend loop
- Update comment to reflect Phase 3C completion

This completes the threading of context through the client bootstrap,
moving away from global mutable state for audio channels, decode channels,
and authentication tokens.

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

src/trx-client/src/main.rs

@@ -98,14 +98,14 @@ fn main() -> DynResult<()> {
 struct AppState;
 
 async fn async_init() -> DynResult<AppState> {
+    use std::sync::Arc;
+
     tracing_subscriber::fmt().with_target(false).init();
 
-    // Phase 3B: Create bootstrap context for explicit initialization.
-    // This replaces reliance on global mutable state, though currently
-    // built-in frontends still register on globals for plugin compatibility.
-    // Full de-globalization would require threading context through spawn_frontend.
+    // Phase 3: Create bootstrap context for explicit initialization.
+    // This replaces reliance on global mutable state by threading context through spawn_frontend.
     let mut _frontend_reg_ctx = FrontendRegistrationContext::new();
-    let mut _frontend_runtime_ctx = FrontendRuntimeContext::new();
+    let frontend_runtime_ctx = Arc::new(FrontendRuntimeContext::new());
 
     register_http_frontend();
     register_http_json_frontend();
@@ -248,7 +248,7 @@ async fn async_init() -> DynResult<AppState> {
         info!("Audio disabled in config, decode will not be available");
     }
 
-    // Spawn frontends
+    // Spawn frontends with runtime context
     for frontend in &frontends {
         let frontend_state_rx = state_rx.clone();
         let addr = match frontend.as_str() {
@@ -265,6 +265,7 @@ async fn async_init() -> DynResult<AppState> {
             tx.clone(),
             callsign.clone(),
             addr,
+            frontend_runtime_ctx.clone(),
         )?;
     }