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/render.py

@@ -2,6 +2,11 @@
 OTF → terminal half-block rendering pipeline.
 Font loading, text rasterization, word-wrap, gradient coloring, headline block assembly.
 Depends on: config, terminal, sources, translate.
+
+.. deprecated::
+    This module contains legacy rendering code. New pipeline code should
+    use the Stage-based pipeline architecture instead. This module is
+    maintained for backwards compatibility with the demo mode.
 """
 
 import random