refactor(structure): promote app to repo root + remove redundant workspace cruft

Standard production layout: the OKR app (was nested under AINative_OKR_CASAN5/) is now
the repository root. No more wrapper directory.

- Promote AINative_OKR_CASAN5/* -> repo root (backend/ frontend/ packages/ apps/
  .specify/ docs/ infra/ nginx/ scripts/ + configs). Merge tool dirs: .gitea (kept the
  active deploy ci.yml, added harness-ci.yml + runbooks), .claude (agents/commands +
  launch.json), .github moved up.
- Remove redundant: 00_SUBMISSION_PACKAGE, scattered root notes (FPT_CASAN_Full.md,
  tu-tuong-casan.md, casan-tu-sinh..., casan_harness_assessment.md, source-review...,
  README_CASAN5_REFINED.md), casan-next-plans/ and optimize-docs/ (competition/planning
  artifacts — roadmap + design history preserved in git log / commit messages).
- Update all references to the old layout:
  - .gitea/workflows/{ci,harness-ci}.yml, .github/workflows/{ci,deploy}.yml:
    working-directory .; drop AINative_OKR_CASAN5/ prefix; .specify/{tests,scripts}
    -> packages/casan-harness/... (.specify/logs state kept)
  - .claude/launch.json, .gitea/*-runbook.md: path prefixes
  - CLAUDE.md, README.md: docs/input -> apps/okr/domain/input
  - policy-bundle.yaml: 8 policy paths -> packages/casan-harness/...; manifest re-signed
- secrets-scan.sh: fixture excludes -> new package/domain paths.

Full gate from the new root: PASS=64 FAIL=0 SKIP=3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,72 @@
+# Dependencies
+node_modules/
+backend/node_modules/
+frontend/node_modules/
+
+# Build outputs
+dist/
+backend/dist/
+frontend/dist/
+frontend/.vite/
+frontend/node_modules/.vite/
+
+# Local environment and secrets
+.env
+.env.*
+!.env.example
+backend/.env
+frontend/.env
+**/.env
+**/.env.*
+*.pem
+*.key
+*.crt
+*.p12
+*.pfx
+
+# Local databases and Prisma runtime files
+*.db
+*.db-journal
+*.sqlite
+*.sqlite3
+backend/prisma/*.db
+backend/prisma/*.db-journal
+
+# Logs and runtime traces
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+.specify/logs/tmp/
+.specify/logs/trace/
+.specify/logs/idempotency/
+.specify/logs/level5/rollback-backups/
+
+# Harness runtime state (loop runs, tenant partitions) — never committed
+.specify/state/
+
+# Python / script cache
+__pycache__/
+*.py[cod]
+.pytest_cache/
+
+# Test and coverage output
+coverage/
+.nyc_output/
+test-results/
+playwright-report/
+
+# OS/editor files
+.DS_Store
+Thumbs.db
+.idea/
+.vscode/
+*.swp
+*.swo
+
+# Local scratch files
+o6.txt
+o7.txt
+t6.txt
+t7.txt