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/pipeline/registry.py

@@ -6,18 +6,25 @@ Provides a single registry for sources, effects, displays, and cameras.
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING, Any, TypeVar
+
 from engine.pipeline.core import Stage
 
+if TYPE_CHECKING:
+    from engine.pipeline.core import Stage
+
+T = TypeVar("T")
+
 
 class StageRegistry:
     """Unified registry for all pipeline stage types."""
 
-    _categories: dict[str, dict[str, type[Stage]]] = {}
+    _categories: dict[str, dict[str, type[Any]]] = {}
     _discovered: bool = False
     _instances: dict[str, Stage] = {}
 
     @classmethod
-    def register(cls, category: str, stage_class: type[Stage]) -> None:
+    def register(cls, category: str, stage_class: type[Any]) -> None:
         """Register a stage class in a category.
 
         Args:
@@ -27,12 +34,11 @@ class StageRegistry:
         if category not in cls._categories:
             cls._categories[category] = {}
 
-        # Use class name as key
         key = getattr(stage_class, "__name__", stage_class.__class__.__name__)
         cls._categories[category][key] = stage_class
 
     @classmethod
-    def get(cls, category: str, name: str) -> type[Stage] | None:
+    def get(cls, category: str, name: str) -> type[Any] | None:
         """Get a stage class by category and name."""
         return cls._categories.get(category, {}).get(name)