fix(excalidraw): fusion imports ESM en un seul module + CSP worker-src/blob:

backend/main.py

@@ -570,11 +570,13 @@ class SecurityHeadersMiddleware(BaseHTTPMiddleware):
         response.headers["Referrer-Policy"] = "strict-origin-when-cross-origin"
         response.headers["Content-Security-Policy"] = (
             "default-src 'self'; "
-            "script-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com https://unpkg.com https://esm.sh https://cdn.jsdelivr.net https://static.cloudflareinsights.com; "
+            "script-src 'self' 'unsafe-inline' blob: https://cdnjs.cloudflare.com https://unpkg.com https://esm.sh https://cdn.jsdelivr.net https://static.cloudflareinsights.com; "
             "style-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com https://fonts.googleapis.com https://cdn.jsdelivr.net; "
             "img-src 'self' data: blob:; "
-            "connect-src 'self' https://esm.sh https://unpkg.com https://cdnjs.cloudflare.com https://fonts.googleapis.com https://fonts.gstatic.com https://cdn.jsdelivr.net; "
-            "font-src 'self' https://fonts.gstatic.com;"
+            "connect-src 'self' blob: https://esm.sh https://unpkg.com https://cdnjs.cloudflare.com https://fonts.googleapis.com https://fonts.gstatic.com https://cdn.jsdelivr.net; "
+            "font-src 'self' data: https://fonts.gstatic.com; "
+            "worker-src 'self' blob:; "
+            "frame-src 'self' blob:;"
         )
         # Cache static assets aggressively (fingerprinted by PWA manifest hash)
         if request.url.path.startswith("/static/"):