feat: add pipeline introspection demo mode

- Add PipelineIntrospectionSource that renders live ASCII DAG with metrics
- Add PipelineMetricsSensor exposing pipeline performance as sensor values
- Add PipelineIntrospectionDemo controller with 3-phase animation:
  - Phase 1: Toggle effects one at a time (3s each)
  - Phase 2: LFO drives intensity default→max→min→default
  - Phase 3: All effects with shared LFO (infinite loop)
- Add pipeline-inspect preset
- Add get_frame_times() to Pipeline for sparkline data
- Add tests for new components
- Update mise.toml with pipeline-inspect preset task

engine/sources_v2.py

@@ -94,38 +94,6 @@ class PoetryDataSource(DataSource):
         return [SourceItem(content=t, source=s, timestamp=ts) for t, s, ts in items]
 
 
-class PipelineDataSource(DataSource):
-    """Data source for pipeline visualization (demo mode). Dynamic - updates every frame."""
-
-    def __init__(self, viewport_width: int = 80, viewport_height: int = 24):
-        self.viewport_width = viewport_width
-        self.viewport_height = viewport_height
-        self.frame = 0
-
-    @property
-    def name(self) -> str:
-        return "pipeline"
-
-    @property
-    def is_dynamic(self) -> bool:
-        return True
-
-    def fetch(self) -> list[SourceItem]:
-        from engine.pipeline_viz import generate_large_network_viewport
-
-        buffer = generate_large_network_viewport(
-            self.viewport_width, self.viewport_height, self.frame
-        )
-        self.frame += 1
-        content = "\n".join(buffer)
-        return [
-            SourceItem(content=content, source="pipeline", timestamp=f"f{self.frame}")
-        ]
-
-    def get_items(self) -> list[SourceItem]:
-        return self.fetch()
-
-
 class MetricsDataSource(DataSource):
     """Data source that renders live pipeline metrics as ASCII art.
 
@@ -340,9 +308,6 @@ class SourceRegistry:
     def create_poetry(self) -> PoetryDataSource:
         return PoetryDataSource()
 
-    def create_pipeline(self, width: int = 80, height: int = 24) -> PipelineDataSource:
-        return PipelineDataSource(width, height)
-
 
 _global_registry: SourceRegistry | None = None