chore: remove all Remotion references from Electron main + UI

- Cleaned Electron main.ts: removed Remotion bundle path, compositor path, and predownloadBrowser()
- Set BRADLY_SERVE_URL from Express port for headless rendering
- Cleaned GlobalSettingsPanel: removed Remotion-specific frame capture code
- Removed stale remotion:bundle script from package.json
- Zero Remotion dependencies, imports, or functional code remain

src/components/properties/GlobalSettingsPanel.tsx

@@ -37,29 +37,16 @@ export const GlobalSettingsPanel: React.FC<GlobalSettingsPanelProps> = ({
     const player = playerRef?.current;
     if (!player) return;
     
-    // Find the remotion-player container and grab its inner canvas/iframe
-    const playerContainer = document.querySelector('[data-remotion-player]') ?? document.querySelector('.remotion-player');
+    // Find the BradlyPlayer container and capture its content
+    const playerContainer = document.querySelector('[data-bradly-player]');
     if (!playerContainer) {
-      // Fallback: find the iframe or video element
-      const iframe = document.querySelector('iframe');
-      if (iframe) {
-        // Can't capture cross-origin iframe, but for same-origin:
-        try {
-          const iframeDoc = iframe.contentDocument;
-          if (iframeDoc) {
-            const canvas = document.createElement('canvas');
-            const body = iframeDoc.body;
-            canvas.width = body.scrollWidth;
-            canvas.height = body.scrollHeight;
-            // This is a simplistic approach - Remotion doesn't expose easy screenshot
-          }
-        } catch { /* cross-origin */ }
-      }
+      // Fallback: use the render API endpoint
+      alert('📸 Exportar frame: Usa el botón "Renderizar" con formato PNG para capturar frames.');
+      return;
     }
     
-    // Use html2canvas-like approach: create a temporary canvas from the player
-    // For now, use a simple screenshot via the Remotion player's renderToCanvas
-    alert('📸 Exportar frame: Esta función requiere @remotion/renderer para renderizar frames individuales. Próximamente disponible.');
+    // TODO: Implement canvas-based screenshot from BradlyPlayer viewport
+    alert('📸 Exportar frame: Usa el botón "Renderizar" con formato PNG para capturar frames.');
   }, [playerRef]);
 
   const matchingPresets = EXPORT_PRESETS.filter(p => p.aspect === aspectRatio);