refactor: add DesignIR distillation pipeline

README.md

@@ -1,3 +1,24 @@
 # CadSet
 
-CAD generation workspace integrating text-to-cad, SimpleCADAPI, and CADAM.
+CAD Router provides three STEP-centered workflows:
+
+- Generate editable CAD from natural-language requests.
+- Generate or modify editable CAD from text plus reference images.
+- Reconstruct uploaded STEP files into editable DesignIR 2.0 and modify them.
+
+For every request, CAD Router selects either text-to-cad or SimpleCADAPI as
+the execution backend. The persistent contract is DesignIR 2.0 plus STEP.
+
+## Project layout
+
+- `cad-agent-studio/`: standalone web frontend.
+- `designir-pipeline/`: role-separated reconstruction, acceptance, and
+  experience-promotion system.
+- `text-to-cad/`: CAD Router, Build123d generation skill, Viewer, and shared
+  CAD runtime.
+- `SimpleCADAPI/`: the second CAD execution backend.
+- `llm.config.yaml`: private, Git-ignored provider configuration shared by the
+  standalone frontend.
+
+The uploaded teacher STEP is evidence only. A reconstruction must compile from
+DesignIR after the teacher file has been removed from the build environment.