Add model-reviewed CAD experience pipeline

text-to-cad/skills/cad-router/references/backend-contract.md

@@ -12,6 +12,12 @@ Capture these fields when known:
 - Part versus assembly, standard components, mating requirements, and motion relationships.
 - Required parameter controls, replay, semantic tags, or FreeCAD interchange.
 - Geometry and visual validation targets.
+- Optional schema `2.0` generalized experience library. Never pass a case
+  DesignIR, teacher STEP, source dimensions, coordinates, or surface references
+  to the selected backend.
+- For modification, accept only an explicitly supplied original model or
+  editable generator plus the promoted library. Never inspect the parser
+  input/output corpus or a private case JSON.
 
 ## Route decision
 
@@ -25,6 +31,9 @@ Record:
 - Workflow profiles such as `requirement_refinement` and `visual_repair`.
 - Focused downstream Skills.
 - Any explicit override and its reason.
+- `operation`: create or modify; for modification also record the explicit
+  source path and whether the route uses native parameter editing, local feature
+  rebuilding, or experience-guided semantic reconstruction.
 
 ## Task manifest
 
@@ -39,7 +48,7 @@ Write `cad-task.json` beside the task artifacts with this minimum shape:
     "runner_skill": "cad",
     "project": "text-to-cad",
     "fallback_order": ["simplecadapi", "cadam"],
-    "workflow_profiles": ["caddesigner_ecip"]
+    "workflow_profiles": ["requirement_refinement", "visual_repair"]
   },
   "source": {
     "path": "connecting_rod.py",
@@ -51,6 +60,11 @@ Write `cad-task.json` beside the task artifacts with this minimum shape:
     {"path": "connecting_rod.stl", "role": "secondary"}
   ],
   "parameters": {},
+  "experience": {
+    "library": "../../../cad-experience-library/library.json",
+    "context_kind": "generalized_cad_experience_query",
+    "methods_applied": []
+  },
   "assumptions": [],
   "validation": [],
   "viewer_links": []