Extract builder nodes

docs/prompt-architecture-improvement-plan.md

@@ -272,10 +272,10 @@ Improve later:
 
 ### Node / UI Path
 
-Owner: `__init__.py`, `node_seed_resolution.py`, `node_camera.py`,
-`node_character.py`, `node_hardcore_position.py`, `node_formatter.py`,
-`node_insta.py`, `node_route_config.py`, `node_profile_filter.py`,
-`loop_nodes.py`, `web/*.js`.
+Owner: `__init__.py`, `node_builder.py`, `node_seed_resolution.py`,
+`node_camera.py`, `node_character.py`, `node_hardcore_position.py`,
+`node_formatter.py`, `node_insta.py`, `node_route_config.py`,
+`node_profile_filter.py`, `loop_nodes.py`, `web/*.js`.
 
 Keep here:
 
@@ -283,6 +283,7 @@ Keep here:
 - widget behavior;
 - button actions;
 - dynamic input slots.
+- direct and config-driven builder node declarations in `node_builder.py`.
 - seed and resolution utility node declarations in `node_seed_resolution.py`.
 - camera utility node declarations in `node_camera.py`.
 - character pool, slot, and profile node declarations in `node_character.py`.
@@ -296,6 +297,8 @@ Keep here:
 
 Already isolated:
 
+- direct and config-driven prompt builder nodes live in `node_builder.py`, with
+  registration maps imported by `__init__.py`.
 - seed/global-seed/seed-locker and SDXL/Krea2 resolution utility nodes live in
   `node_seed_resolution.py`, with registration maps imported by `__init__.py`.
 - camera/orbit/Qwen translator utility nodes live in `node_camera.py`, with