feat(sub12a): JSONRPC endpoints for the Simple Recipe Editor

11 routes under /fp/simple_recipe/...:
  load
  library/{list,create,write,delete}
  step/{insert,write,remove,reorder}
  template/{list,import}

Library/template imports snapshot-copy fields (Q4 = A locked) — no
live references. The _SNAPSHOT_FIELDS + _INPUT_SNAPSHOT_FIELDS module
constants are the single source of truth for what gets copied;
adding a new authoring field on fp.step.template means appending it
once to _SNAPSHOT_FIELDS and the controller stays correct.

library_delete is soft when nodes still reference the template via
source_template_id (operator can't accidentally orphan recipe steps).

Uses recipe.check_access('read') (Odoo 19 unified API) instead of the
older check_access_rights/check_access_rule pair.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating/controllers/__init__.py

@@ -3,3 +3,4 @@
 # License OPL-1 (Odoo Proprietary License v1.0)
 
 from . import recipe_controller
+from . import simple_recipe_controller