fix: show backstage films on all content sources, not just IndeeHub API

The filmmakerService.usesSelfHosted() was tied to the content source
toggle, returning true only for 'indeehub-api'. When the user switched
to 'topdocfilms' or 'indeehub', the mergePublishedFilmmakerProjects()
function routed filmmaker API calls to the wrong (external) API, so
backstage-created films never appeared.

Now in production (USE_MOCK=false), filmmaker operations always use
the self-hosted backend regardless of which content catalog is active.
The content source toggle only affects the browse page catalog display.

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

docker-compose.yml

@@ -20,7 +20,7 @@ services:
       context: .
       dockerfile: Dockerfile
       args:
-        CACHEBUST: "15"
+        CACHEBUST: "16"
         VITE_USE_MOCK_DATA: "false"
         VITE_CONTENT_ORIGIN: ${FRONTEND_URL}
         VITE_INDEEHUB_API_URL: /api

src/services/filmmaker.service.ts

@@ -10,6 +10,7 @@
 import { apiService } from './api.service'
 import { indeehubApiService } from './indeehub-api.service'
 import { useContentSourceStore } from '../stores/contentSource'
+import { USE_MOCK } from '../utils/mock'
 import type {
   ApiProject,
   ApiContent,
@@ -26,9 +27,16 @@ import type {
 } from '../types/api'
 
 /**
- * Check if we should route requests to our self-hosted backend
+ * Check if we should route requests to our self-hosted backend.
+ *
+ * In production (USE_MOCK = false) the self-hosted API is always
+ * available, so filmmaker operations always use it regardless of
+ * which content catalog is active on the browse page.
+ * In dev/mock mode, only route to self-hosted when the content
+ * source explicitly selects 'indeehub-api'.
  */
 function usesSelfHosted(): boolean {
+  if (!USE_MOCK) return true
   const store = useContentSourceStore()
   return store.activeSource === 'indeehub-api'
 }