[webapp] Add retry logic and improve renderer registration

- Added automatic retries with exponential backoff to fetchRenderers
- Improved WebRenderer registration: handle stale players, avoid duplicate registrations,
  and force renderers refresh after successful connection
- Bumped version to v0.3.37 (Cargo: 0.3.36 → Cargo.lock mismatch fixed by updating to final version)

pmoapp/webapp/src/composables/useWebRenderer.ts

@@ -73,17 +73,41 @@ export function useWebRenderer() {
     let onConnectedCallback: (() => void) | null = null;
 
     async function register(): Promise<void> {
-        // Prevent concurrent registrations (race condition → double player)
-        if (globalPlayer || registering) {
+        // Allow re-registration if we have a stale player but no connection
+        if (globalPlayer && !connected.value) {
+            console.log('[WebRenderer] stale globalPlayer, clearing');
+            globalPlayer = null;
+        }
+        
+        if (globalPlayer) {
+            player = globalPlayer;
+            connected.value = true;
+            console.log('[WebRenderer] reusing existing player');
+            return;
+        }
+
+        if (registering) {
+            console.log('[WebRenderer] already registering, waiting...');
+            // Wait a bit and try once
+            await new Promise(r => setTimeout(r, 1000));
             if (globalPlayer) {
                 player = globalPlayer;
                 connected.value = true;
+                return;
             }
-            return;
         }
+        
         registering = true;
 
-        const instanceId = getOrCreateInstanceId();
+        let instanceId;
+        try {
+            instanceId = getOrCreateInstanceId();
+        } catch (e) {
+            console.error('[WebRenderer] failed to get instanceId:', e);
+            registering = false;
+            return;
+        }
+        
         console.log('[WebRenderer] registering with instanceId:', instanceId);
 
         try {
@@ -122,6 +146,13 @@ export function useWebRenderer() {
 
             connected.value = true;
             onConnectedCallback?.();
+            
+            // Force refresh renderers list after registration
+            // The SSE might miss the initial event
+            setTimeout(() => {
+                console.log('[WebRenderer] forcing renderers refresh');
+                window.dispatchEvent(new CustomEvent('webrenderer-registered'));
+            }, 500);
         } catch (e) {
             console.error("[WebRenderer] register error:", e);
         } finally {