feat(benchmark): add hook mode with baseline cache for pre-push checks

- Fix lint errors and LSP issues in benchmark.py
- Add --hook mode to compare against saved baseline
- Add --baseline flag to save results as baseline
- Add --threshold to configure degradation threshold (default 20%)
- Add benchmark step to pre-push hook in hk.pkl
- Update AGENTS.md with hk documentation links and benchmark runner docs

engine/benchmark.py

@@ -120,30 +120,17 @@ def benchmark_effect_with_display(
     old_stderr = sys.stderr
 
     try:
-        from engine.effects.types import EffectConfig, EffectContext
-
         sys.stdout = StringIO()
         sys.stderr = StringIO()
 
         effect = effect_class()
-        effect.configure(EffectConfig(enabled=True, intensity=1.0))
-
-        ctx = EffectContext(
-            terminal_width=80,
-            terminal_height=24,
-            scroll_cam=0,
-            ticker_height=0,
-            mic_excess=0.0,
-            grad_offset=0.0,
-            frame_number=0,
-            has_message=False,
-        )
+        effect.configure(enabled=True, intensity=1.0)
 
         times = []
         chars = sum(len(line) for line in buffer)
 
         for _ in range(iterations):
-            processed = effect.process(buffer, ctx)
+            processed = effect.process(buffer)
             t0 = time.perf_counter()
             display.show(processed)
             elapsed = (time.perf_counter() - t0) * 1000
@@ -213,13 +200,6 @@ def get_available_effects():
     """Get available effect classes."""
     try:
         from engine.effects import get_registry
-
-        try:
-            from effects_plugins import discover_plugins
-
-            discover_plugins()
-        except Exception:
-            pass
     except Exception:
         return []
 
@@ -228,8 +208,7 @@ def get_available_effects():
 
     for name, effect in registry.list_all().items():
         if effect:
-            effect_cls = type(effect)
-            effects.append((name, effect_cls))
+            effects.append((name, effect))
 
     return effects