Extract shared POV policy

docs/prompt-architecture-improvement-plan.md

@@ -182,6 +182,10 @@ Already isolated:
   camera-scene prose lives in `scene_camera_adapters.py`; row-level camera
   insertion, contextual coworking composition mutation, subject-kind detection,
   and POV suppression live in `row_camera.py`.
+- shared POV slot detection, label merging/filtering, builder-side POV
+  directives, source role-graph viewer replacement, and shared composition
+  cleanup live in `pov_policy.py`; prompt builder and Krea POV routes delegate
+  to it.
 - shared hardcore environment-anchor cleanup lives in
   `hardcore_text_cleanup.py` and normalizes malformed pool joins before metadata
   reaches formatter routes.
@@ -263,8 +267,9 @@ Already isolated:
   POV formatter routes.
 - `hardcore_action_metadata.py` owns shared action-family constants,
   normalization, and inference used by the builder and Krea formatter route.
-- `krea_pov.py` owns POV labels, POV label filtering, and POV camera/composition
-  support text.
+- `pov_policy.py` owns shared POV labels, label filtering, source role-graph
+  viewer replacement, and composition cleanup; `krea_pov.py` owns Krea-specific
+  POV camera support text while delegating shared POV policy.
 - `krea_detail.py` owns generic detail-clause splitting, deduping, joining, and
   density limiting for Krea action prose.
 - `krea_action_positions.py` owns non-POV pose anchors, body-arrangement text,