refactor: Make EffectPlugin an abstract base class, update effects to inherit from it, and improve plugin discovery.

engine/effects/types.py

@@ -1,3 +1,4 @@
+from abc import ABC, abstractmethod
 from dataclasses import dataclass, field
 from typing import Any
 
@@ -8,10 +9,11 @@ class EffectContext:
     terminal_height: int
     scroll_cam: int
     ticker_height: int
-    mic_excess: float
-    grad_offset: float
-    frame_number: int
-    has_message: bool
+    camera_x: int = 0
+    mic_excess: float = 0.0
+    grad_offset: float = 0.0
+    frame_number: int = 0
+    has_message: bool = False
     items: list = field(default_factory=list)
 
 
@@ -22,15 +24,42 @@ class EffectConfig:
     params: dict[str, Any] = field(default_factory=dict)
 
 
-class EffectPlugin:
+class EffectPlugin(ABC):
     name: str
     config: EffectConfig
 
-    def process(self, buf: list[str], ctx: EffectContext) -> list[str]:
-        raise NotImplementedError
+    @abstractmethod
+    def process(self, buf: list[str], ctx: EffectContext) -> list[str]: ...
 
-    def configure(self, config: EffectConfig) -> None:
-        raise NotImplementedError
+    @abstractmethod
+    def configure(self, config: EffectConfig) -> None: ...
+
+
+def create_effect_context(
+    terminal_width: int = 80,
+    terminal_height: int = 24,
+    scroll_cam: int = 0,
+    ticker_height: int = 0,
+    camera_x: int = 0,
+    mic_excess: float = 0.0,
+    grad_offset: float = 0.0,
+    frame_number: int = 0,
+    has_message: bool = False,
+    items: list | None = None,
+) -> EffectContext:
+    """Factory function to create EffectContext with sensible defaults."""
+    return EffectContext(
+        terminal_width=terminal_width,
+        terminal_height=terminal_height,
+        scroll_cam=scroll_cam,
+        ticker_height=ticker_height,
+        camera_x=camera_x,
+        mic_excess=mic_excess,
+        grad_offset=grad_offset,
+        frame_number=frame_number,
+        has_message=has_message,
+        items=items or [],
+    )
 
 
 @dataclass