fix: ListDataSource cache and camera dependency resolution

Two critical fixes:

1. ListDataSource Cache Bug
   - Previously, ListDataSource.__init__ cached raw tuples directly
   - get_items() would return cached raw tuples without converting to SourceItem
   - This caused SourceItemsToBufferStage to receive tuples and stringify them
   - Results: ugly tuple representations in terminal/pygame instead of formatted text
   - Fix: Store raw items in _raw_items, let fetch() convert to SourceItem
   - Cache now contains proper SourceItem objects

2. Camera Dependency Resolution
   - CameraStage declared dependency on 'source.items' exactly
   - DataSourceStage provides 'source.headlines' (or 'source.poetry', etc.)
   - Capability matching didn't trigger prefix match for exact dependency
   - Fix: Change CameraStage dependency to 'source' for prefix matching

3. Added app.py Camera Stage Support
   - Pipeline now adds camera stage from preset.camera config
   - Supports vertical, horizontal, omni, floating, bounce modes
   - Tests now passing with proper data flow through all stages

Tests: All 502 tests passing, 16 skipped

engine/pipeline/adapters.py

@@ -254,7 +254,9 @@ class CameraStage(Stage):
 
     @property
     def dependencies(self) -> set[str]:
-        return {"source.items"}
+        return {
+            "source"
+        }  # Prefix match any source (source.headlines, source.poetry, etc.)
 
     def process(self, data: Any, ctx: PipelineContext) -> Any:
         """Apply camera transformation to data."""
@@ -334,7 +336,7 @@ class FontStage(Stage):
         if data is None:
             return None
 
-        from engine.legacy.render import make_block
+        from engine.render import make_block
 
         w = ctx.params.viewport_width if ctx.params else 80
 
@@ -361,8 +363,8 @@ class FontStage(Stage):
                     ts = "0"
 
                 try:
-                    block = make_block(title, src, ts, w)
-                    result.extend(block)
+                    block_lines, color_code, meta_idx = make_block(title, src, ts, w)
+                    result.extend(block_lines)
                 except Exception:
                     result.append(title)
 
@@ -403,10 +405,14 @@ class ImageToTextStage(Stage):
         return "transform"
 
     @property
-    def capabilities(self) -> set[str]:
+    def outlet_types(self) -> set:
         from engine.pipeline.core import DataType
 
-        return {f"transform.{self.name}", DataType.TEXT_BUFFER}
+        return {DataType.TEXT_BUFFER}
+
+    @property
+    def capabilities(self) -> set[str]:
+        return {f"transform.{self.name}", "render.output"}
 
     @property
     def dependencies(self) -> set[str]: