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/kb/_history.md

@@ -0,0 +1,22 @@
+# Knowledge Base History — Hydrotech Beam
+
+All modifications tracked by generation.
+
+---
+
+## Gen 001 — 2026-02-09 — Initial KB
+
+**Source:** Project intake (CONTEXT.md) + Technical Lead breakdown (BREAKDOWN.md)
+**Author:** Manager 🎯
+
+**Created:**
+- `components/sandwich-beam.md` — initial component file from intake data
+- `materials/steel-aisi.md` — material placeholder
+- `fea/models/sol101-static.md` — FEA model placeholder from breakdown
+- `dev/gen-001.md` — generation document
+
+**Key findings from breakdown:**
+- Baseline FAILS displacement constraint (22 mm vs 10 mm limit)
+- Feasible region may be narrow — stiffness and mass compete
+- Sandwich effect (core thickness) is the primary stiffness lever
+- 9 gaps identified requiring CEO input before proceeding