Adding fixes to the pipeline

gnommo/renderer.py

@@ -269,17 +269,23 @@ def build_ffmpeg_command(plan: RenderPlan, output_path: Path) -> list[str]:
         always_visible_inputs.append(input_idx)
         input_idx += 1
 
-    # Input: background image/video (if specified)
-    from .cache import resolve_with_cache
-    bg_file = plan.config.background or plan.config.background_video
-    has_background = bool(bg_file)
+    # Input: background — resolved via handle in shared_assets/videos.json
+    import json as _json
+    bg_handle = plan.config.background
+    has_background = bool(bg_handle)
     bg_idx = None
     bg_is_image = False
     if has_background:
-        bg_path = project_path / bg_file
-        bg_path, _ = resolve_with_cache(bg_path, project_path)
+        shared_assets_dir = project_path.parent / "shared_assets"
+        videos_json_bg = shared_assets_dir / "videos.json"
+        if not videos_json_bg.exists():
+            raise RenderError(f"shared_assets/videos.json not found (needed for background handle '{bg_handle}')")
+        bg_videos = _json.loads(videos_json_bg.read_text())
+        if bg_handle not in bg_videos:
+            raise RenderError(f"Background handle '{bg_handle}' not found in shared_assets/videos.json")
+        bg_path = shared_assets_dir / bg_videos[bg_handle]["source_file"]
         if not bg_path.exists():
-            bg_path = project_path.parent / bg_file
+            raise RenderError(f"Background file not found: {bg_path} (from handle '{bg_handle}')")
         image_extensions = {".png", ".jpg", ".jpeg", ".gif", ".bmp", ".tiff", ".webp"}
         bg_is_image = bg_path.suffix.lower() in image_extensions
         # Loop background videos infinitely