fix(main): Add render stage for non-headline sources

engine/app/main.py

@@ -84,6 +84,7 @@ def run_pipeline_mode_direct():
         --pipeline-ui: Enable UI panel (BorderMode.UI)
         --pipeline-border <mode>: off, simple, ui
     """
+    import engine.effects.plugins as effects_plugins
     from engine.camera import Camera
     from engine.data_sources.pipeline_introspection import PipelineIntrospectionSource
     from engine.data_sources.sources import EmptyDataSource, ListDataSource
@@ -92,6 +93,9 @@ def run_pipeline_mode_direct():
         ViewportFilterStage,
     )
 
+    # Discover and register all effect plugins
+    effects_plugins.discover_plugins()
+
     # Parse CLI arguments
     source_name = None
     effect_names = []
@@ -285,6 +289,11 @@ def run_pipeline_mode_direct():
             "viewport_filter", ViewportFilterStage(name="viewport-filter")
         )
         pipeline.add_stage("font", FontStage(name="font"))
+    else:
+        # Fallback to simple conversion for other sources
+        from engine.pipeline.adapters import SourceItemsToBufferStage
+
+        pipeline.add_stage("render", SourceItemsToBufferStage(name="items-to-buffer"))
 
     # Add camera
     speed = getattr(params, "camera_speed", 1.0)
@@ -394,7 +403,8 @@ def run_pipeline_mode_direct():
 
             result = pipeline.execute(source_items)
             if not result.success:
-                print("  \033[38;5;196mPipeline execution failed\033[0m")
+                error_msg = f" ({result.error})" if result.error else ""
+                print(f"  \033[38;5;196mPipeline execution failed{error_msg}\033[0m")
                 break
 
             # Render with UI panel