Extract hardcore role graph builder

docs/prompt-architecture-improvement-plan.md

@@ -95,12 +95,13 @@ Keep here:
 
 Move or isolate later:
 
-- role graph generation for hardcore interaction categories into a dedicated
-  module, for example `hardcore_role_graphs.py`;
 - category-library loading and inheritance helpers into `category_library.py`.
 
 Already isolated:
 
+- hardcore configured-cast role graph generation lives in
+  `hardcore_role_graphs.py`; `prompt_builder.py` selects item/axis metadata and
+  then asks that module for the source role graph.
 - camera-scene prose and coworking composition adaptation live in
   `scene_camera_adapters.py`; `prompt_builder.py` still owns camera config
   parsing and row mutation.
@@ -357,7 +358,7 @@ Medium-term:
 
 1. Split `__init__.py` node classes by family after behavior is covered by smoke
    checks.
-2. Extract hardcore role graph generation from `prompt_builder.py` into a
-   dedicated `hardcore_role_graphs.py` module.
+2. Split the internals of `hardcore_role_graphs.py` by action family once more
+   generated edge cases are covered by smoke fixtures.
 3. Add more route-level smoke fixtures for generated edge cases that are not
    covered by the current static Krea/SDXL/caption metadata fixtures.