chore(pipeline): improve pipeline architecture

- Add capability-based dependency resolution with prefix matching
- Add EffectPluginStage with sensor binding support
- Add CameraStage adapter for camera integration
- Add DisplayStage adapter for display integration
- Add Pipeline metrics collection
- Add deprecation notices to legacy modules
- Update app.py with pipeline integration

engine/app.py

@@ -352,7 +352,18 @@ def pick_effects_config():
 
 
 def run_demo_mode():
-    """Run demo mode - showcases effects and camera modes with real content."""
+    """Run demo mode - showcases effects and camera modes with real content.
+
+    .. deprecated::
+        This is legacy code. Use run_pipeline_mode() instead.
+    """
+    import warnings
+
+    warnings.warn(
+        "run_demo_mode is deprecated. Use run_pipeline_mode() instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     import random
 
     from engine import config
@@ -559,7 +570,18 @@ def run_demo_mode():
 
 
 def run_pipeline_demo():
-    """Run pipeline visualization demo mode - shows ASCII pipeline animation."""
+    """Run pipeline visualization demo mode - shows ASCII pipeline animation.
+
+    .. deprecated::
+        This demo mode uses legacy rendering. Use run_pipeline_mode() instead.
+    """
+    import warnings
+
+    warnings.warn(
+        "run_pipeline_demo is deprecated. Use run_pipeline_mode() instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     import time
 
     from engine import config
@@ -700,7 +722,18 @@ def run_pipeline_demo():
 
 
 def run_preset_mode(preset_name: str):
-    """Run mode using animation presets."""
+    """Run mode using animation presets.
+
+    .. deprecated::
+        Use run_pipeline_mode() with preset parameter instead.
+    """
+    import warnings
+
+    warnings.warn(
+        "run_preset_mode is deprecated. Use run_pipeline_mode() instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
     from engine import config
     from engine.animation import (
         create_demo_preset,
@@ -839,28 +872,41 @@ def run_preset_mode(preset_name: str):
 
 def main():
     from engine import config
+    from engine.pipeline import list_presets
 
+    # Show pipeline diagram if requested
     if config.PIPELINE_DIAGRAM:
-        from engine.pipeline import generate_pipeline_diagram
-
+        try:
+            from engine.pipeline import generate_pipeline_diagram
+        except ImportError:
+            print("Error: pipeline diagram not available")
+            return
         print(generate_pipeline_diagram())
         return
 
-    if config.PIPELINE_MODE:
-        run_pipeline_mode(config.PIPELINE_PRESET)
-        return
-
-    if config.PIPELINE_DEMO:
-        run_pipeline_demo()
-        return
+    # Unified preset-based entry point
+    # All modes are now just presets
+    preset_name = None
 
+    # Check for --preset flag first
     if config.PRESET:
-        run_preset_mode(config.PRESET)
-        return
+        preset_name = config.PRESET
+    # Check for legacy --pipeline flag (mapped to demo preset)
+    elif config.PIPELINE_MODE:
+        preset_name = config.PIPELINE_PRESET
+    # Default to demo if no preset specified
+    else:
+        preset_name = "demo"
 
-    if config.DEMO:
-        run_demo_mode()
-        return
+    # Validate preset exists
+    available = list_presets()
+    if preset_name not in available:
+        print(f"Error: Unknown preset '{preset_name}'")
+        print(f"Available presets: {', '.join(available)}")
+        sys.exit(1)
+
+    # Run with the selected preset
+    run_pipeline_mode(preset_name)
 
     atexit.register(lambda: print(CURSOR_ON, end="", flush=True))
 
@@ -1079,6 +1125,11 @@ def run_pipeline_mode(preset_name: str = "demo"):
             if result.success:
                 display.show(result.data)
 
+            if hasattr(display, "is_quit_requested") and display.is_quit_requested():
+                if hasattr(display, "clear_quit_request"):
+                    display.clear_quit_request()
+                raise KeyboardInterrupt()
+
             time.sleep(1 / 60)
             frame += 1