docs: rewrite DEVELOPMENT.md (current state), add scripts/README.md
- Layout: tests/ per workspace, scripts/ tools, docs/ structure
- Test section: 4 types (unit/integration/characterization/scenario),
counts (134 green + 1 validated skip), per-file run, scenario slow note
- Tools section: replay-combat (live demo), audit-rotation (rotation),
audit-state (9 invariant classes)
- Storage: generic KV, path norm, STORAGE_MODE flow, test layers
- Status: M2/M3 done, M4 next
- scripts/README.md: tool usage + bug-finder not unit test
david raistrick
912c493974