Adding fixes to the pipeline

gnommo/validator.py

@@ -84,6 +84,10 @@ def validate_project(
                 )
             continue
 
+        # Segment markers are structural annotations, not slide references
+        if marker.startswith("segment:"):
+            continue
+
         if marker not in slides:
             issues.append(
                 ValidationIssue(
@@ -166,23 +170,37 @@ def validate_project(
                     )
                 )
 
-    # Check background exists (image or video)
-    # Try 'background' first, fall back to deprecated 'background_video'
-    bg_file = config.background or config.background_video
-    if bg_file:
-        # Check in project folder first, then parent (for shared_assets)
-        bg_path = project_path / bg_file
-        bg_path, _ = resolve_with_cache(bg_path, project_path)
-        if not bg_path.exists():
-            # Try parent directory (shared_assets at repo root)
-            bg_path = project_path.parent / bg_file
-            bg_path, _ = resolve_with_cache(bg_path, project_path.parent)
-        if not bg_path.exists():
+    # Check background exists — must be a handle in shared_assets/videos.json
+    bg_handle = config.background
+    if bg_handle:
+        shared_assets_dir = project_path.parent / "shared_assets"
+        videos_json_path_bg = shared_assets_dir / "videos.json"
+        if not videos_json_path_bg.exists():
             issues.append(
                 ValidationIssue(
-                    f"Background not found: {bg_file}", project_path / "project.json"
+                    f"shared_assets/videos.json not found (needed for background handle '{bg_handle}')",
+                    project_path / "project.json",
                 )
             )
+        else:
+            import json as _json
+            bg_videos = _json.loads(videos_json_path_bg.read_text())
+            if bg_handle not in bg_videos:
+                issues.append(
+                    ValidationIssue(
+                        f"Background handle '{bg_handle}' not found in shared_assets/videos.json",
+                        project_path / "project.json",
+                    )
+                )
+            else:
+                bg_path = shared_assets_dir / bg_videos[bg_handle]["source_file"]
+                if not bg_path.exists():
+                    issues.append(
+                        ValidationIssue(
+                            f"Background file not found: {bg_path} (from handle '{bg_handle}')",
+                            project_path / "project.json",
+                        )
+                    )
 
     # Check we have at least one video source
     if not videos: