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/skills/golden-file-normalizer/SKILL.md

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+---
+name: golden-file-normalizer
+description: Guidance and recipes for writing normalization rules that make SUT output files deterministic for golden-file regression testing. Use when designing or extending the normalizer module, or when diagnosing diff noise.
+---
+
+# Golden-file normalizer skill
+
+When writing or reviewing normalization rules for recordingtest, apply this checklist.
+
+## Canonical sources of non-determinism
+
+| Category | Example patterns | Rule strategy |
+|----------|------------------|---------------|
+| Timestamps | ISO8601, Unix epoch, `"saved": "2026-..."` | Replace with `<TS>` or strip key |
+| GUIDs / UUIDs | `xxxxxxxx-xxxx-...` | Replace with `<GUID-N>` (stable index per occurrence) |
+| Absolute paths | `C:\Users\...\`, `D:\MYCLAUDE_PROJECT\...` | Replace repo root with `<REPO>`, user with `<USER>` |
+| Recent files | `RecentFiles.json` | Empty the list or mask entirely |
+| Float precision | `3.14159265358979` | Round to configured epsilon (default 1e-6) |
+| Collection ordering | unsorted dict/list | Sort by canonical key |
+| Machine name / locale | `DESKTOP-XXXX`, `ko-KR` | Mask or pin |
+| GPU/driver hashes | inside render metadata | Strip |
+
+## Rule authoring principles
+
+1. **Rules are versioned** — bump the normalizer profile when adding/removing rules; scenarios pin a profile.
+2. **Never hide real bugs** — mask only fields proven non-deterministic across 3+ clean runs.
+3. **Text first** — parse JSON/XML semantically; use regex only as fallback.
+4. **Bidirectional tests** — every rule has a unit test with before/after samples.
+5. **Log what you normalized** — emit a sidecar `normalization.log` listing replacements for diagnostics.
+
+## Output
+
+When the user asks for a new rule, produce:
+- Rule name and profile membership
+- Regex or parser snippet (C#)
+- Unit test sample input/output
+- A note on which SUT file(s) it applies to