perf(desktop): reduce CPU/GPU overhead in Tauri shell

- SSH monitor: adaptive polling 2s→10s after stabilization, cheap TCP
  probe before expensive SSH subprocess check
- SSH setup: exponential backoff in wait_for_master_ready and
  wait_local_forward_ready (250ms→2s cap)
- Health checks: exponential backoff (100ms→1s / 250ms→2s) instead of
  flat intervals
- Startup recovery poll: cap at 15 retries instead of infinite
- Remove webview log target in release builds (eliminates IPC overhead)
- Set global NO_PROXY env var at startup for all loopback addresses
- Remove reqwest::blocking feature; use raw TCP for sidecar shutdown and
  SSH health checks
- Disable pinch-to-zoom on macOS via WKWebView.setAllowsMagnification
- Add WebView2 browser args on Windows (proxy bypass + disable unused
  UI features)
- Add Cargo release profile: thin LTO, codegen-units=1, strip
- Extract apply_platform_window_config for consistent window setup
- Add vibrancy toggle in Appearance settings (macOS desktop only) with
  solid background fallback when disabled

packages/ui/src/App.tsx

@@ -277,6 +277,8 @@ function App({ apis }: AppProps) {
     if (providersCount > 0 && agentsCount > 0) return;
 
     let active = true;
+    let retries = 0;
+    const MAX_RETRIES = 15;
     const attempt = async () => {
       const state = useConfigStore.getState();
       if (state.providers.length > 0 && state.agents.length > 0) return;
@@ -287,7 +289,11 @@ function App({ apis }: AppProps) {
     };
 
     void attempt();
-    const id = setInterval(() => { if (active) void attempt(); }, 2000);
+    const id = setInterval(() => {
+      if (!active) return;
+      if (++retries >= MAX_RETRIES) { clearInterval(id); return; }
+      void attempt();
+    }, 2000);
     return () => { active = false; clearInterval(id); };
   }, [isConnected, isVSCodeRuntime, loadAgents, loadProviders, providersCount, agentsCount]);