Set up AI dev environment for recordingtest (#2)

- CLAUDE.md with collaboration rules and Planner/Generator/Evaluator cycle
- .claude/ agents, commands, skills, hooks per Claude Code conventions
- Sprint Contracts for sut-prober, normalizer, recorder, player, diff-reporter
- SUT catalog (EG-BIM Modeler, 187 plugins) and .gitignore excluding SUT tree
- PROGRESS.md / PLAN.md as shared agent handoff state
- Solution scaffold targeting sut-prober PoC

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.claude/commands/handoff.md

@@ -0,0 +1,23 @@
+---
+name: handoff
+description: Session handoff — update PROGRESS.md, PLAN.md, and write the history file in one go before ending a work session.
+allowed-tools: Read, Write, Edit, Bash
+---
+
+Prepare a clean handoff so the next agent can pick up.
+
+Steps:
+
+1. Read `PROGRESS.md` and `PLAN.md`. If either is missing, create a skeleton.
+2. Ask the user (or infer from the session) what was completed, what is in progress, and what is blocked.
+3. Update `PROGRESS.md`:
+   - Move completed items to "Done" with date and artifact paths.
+   - Mark in-progress items with current owner and status.
+4. Update `PLAN.md`:
+   - Remove completed items.
+   - Add any newly discovered follow-ups.
+   - Re-order priorities if needed.
+5. Write `docs/history/YYYY-MM-DD_{작업명}.md` with **소요 시간**, **Context 사용량**, 이슈 번호, 산출물.
+6. Confirm all three files are saved and list their paths.
+
+Arguments: `$ARGUMENTS` — optional short description to seed the history file title.