docs: add research domains and resource registry

- add local external resources registry
- add research domain contract and per-repository research domains
- add raw fact snapshot governance and validation scripts

Validation:
- make test
- git diff --check HEAD~1..HEAD

Note:
- welcome workflow failed because its action input names are stale; core content CI passed.

docs/research/daotin-ai-coding/domain.yml

@@ -0,0 +1,32 @@
+version: 1
+repo:
+  name: Daotin/ai-coding
+  source_name: Daotin/ai-coding
+  url: https://github.com/Daotin/ai-coding
+research:
+  domain_id: daotin-ai-coding
+  domain_name: Daotin/ai-coding 研究域
+  primary_direction: workflow-methodology
+  role: AI Coding 经验汇总
+  priority: 3
+  why_study: 适合补充 Cursor、Claude Code、Codex、MCP、AGENTS.md 等实践素材。
+github_observed:
+  observed_at: '2026-07-03'
+  source: gh repo view
+  stars: 65
+  forks: 6
+  archived: false
+  language: null
+  license: mit
+  default_branch: main
+  pushed_at: '2026-01-24T13:27:57Z'
+  updated_at: '2026-07-02T10:34:32Z'
+  latest_release: null
+  homepage: ''
+  topics: []
+source_evidence:
+  file: ChatGPT-中文Vibe Coding仓库 (2).md
+  line: 35
+maintenance:
+  fact_policy: GitHub 动态字段只代表 observed_at 当日快照，更新结论前必须重新核验。
+  split_policy: 本目录已经是一等研究域；更深分析放入本目录新增文档。