Restructure Hydrotech Beam project — KB-integrated layout

New project structure with knowledge base integration:
- kb/ with components, materials, fea, dev generations
- models/ for reference NX files (golden copies)
- studies/ for self-contained optimization campaigns
- deliverables/ for final outputs
- DECISIONS.md decision log (6 decisions tracked)
- BREAKDOWN.md (moved from 1_breakdown/)
- Gen 001 created from intake + technical breakdown

KB extension file: atomizer/shared/skills/knowledge-base-atomizer-ext.md

Refs: DEC-HB-004, DEC-HB-005, DEC-HB-006

projects/hydrotech-beam/models/README.md

@@ -0,0 +1,23 @@
+# Reference Models — Hydrotech Beam
+
+Golden copies of the NX model files. **Do not modify these directly.**
+
+Studies should copy these to their own `model/` folder and modify there.
+
+## Files
+
+| File | Description | Status |
+|------|-------------|--------|
+| `Beam.prt` | NX CAD part — sandwich I-beam with lightening holes | ⏳ Pending upload |
+| `Beam_fem1.fem` | FEM mesh file | ⏳ Pending upload |
+| `Beam_fem1_i.prt` | Idealized part for FEM | ⏳ Pending upload |
+| `Beam_sim1.sim` | Simulation file — SOL 101 static | ⏳ Pending upload |
+
+## Key Expression
+
+- `p173` — beam mass (kg)
+
+## Notes
+
+- Model files will be added once Syncthing/file transfer is set up
+- Verify model rebuild across full design variable range before optimization