docs(session): add restart-safe recovery workflow

Context:

- codex cli 중단 후에도 작업 품질과 맥락을 안정적으로 복구하기 위해

Changes:

- docs/00~07, 90 문서 세트 추가/정리

- commit convention 문서 및 .gitmessage-session.txt 템플릿 추가

- scripts/session/recover-context.sh 추가

- package.json에 session:recover 스크립트 추가

Validation:

- npm run session:recover

Session-State: session recovery docs, template, and script are in place

Session-Next: apply this commit format to feature and refactor commits

Session-Risks: legacy commits before this change do not include session trailers

package.json

@@ -7,7 +7,8 @@
     "build": "next build",
     "start": "next start",
     "lint": "eslint",
-    "local": "cross-env NEXT_PUBLIC_API_BASE_URL=http://localhost:8080 next dev"
+    "local": "cross-env NEXT_PUBLIC_API_BASE_URL=http://localhost:8080 next dev",
+    "session:recover": "bash scripts/session/recover-context.sh"
   },
   "dependencies": {
     "@react-oauth/google": "^0.13.4",