Fix poster 404: add ^~ to /storage/ locations to override static asset regex

Nginx was serving /storage/.../*.jpg from the local filesystem instead of
proxying to MinIO because the static asset regex location (~* \.(jpg|...)$)
takes priority over plain prefix locations. Adding ^~ ensures the /storage/
and /storage-private/ prefix locations always win over regex matches.

Same root cause as the earlier 405 on thumbnail uploads.

Co-authored-by: Cursor <cursoragent@cursor.com>

docker-compose.yml

@@ -20,7 +20,7 @@ services:
       context: .
       dockerfile: Dockerfile
       args:
-        CACHEBUST: "11"
+        CACHEBUST: "13"
         VITE_USE_MOCK_DATA: "false"
         VITE_CONTENT_ORIGIN: ${FRONTEND_URL}
         VITE_INDEEHUB_API_URL: /api