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>

packages/casan-harness/templates/checklist-template.md

@@ -0,0 +1,40 @@
+# [CHECKLIST TYPE] Checklist: [FEATURE NAME]
+
+**Purpose**: [Brief description of what this checklist covers]
+**Created**: [DATE]
+**Feature**: [Link to spec.md or relevant documentation]
+
+**Note**: This checklist is generated by the `/speckit.checklist` command based on feature context and requirements.
+
+<!-- 
+  ============================================================================
+  IMPORTANT: The checklist items below are SAMPLE ITEMS for illustration only.
+  
+  The /speckit.checklist command MUST replace these with actual items based on:
+  - User's specific checklist request
+  - Feature requirements from spec.md
+  - Technical context from plan.md
+  - Implementation details from tasks.md
+  
+  DO NOT keep these sample items in the generated checklist file.
+  ============================================================================
+-->
+
+## [Category 1]
+
+- [ ] CHK001 First checklist item with clear action
+- [ ] CHK002 Second checklist item
+- [ ] CHK003 Third checklist item
+
+## [Category 2]
+
+- [ ] CHK004 Another category item
+- [ ] CHK005 Item with specific criteria
+- [ ] CHK006 Final item in this category
+
+## Notes
+
+- Check items off as completed: `[x]`
+- Add comments or findings inline
+- Link to relevant resources or documentation
+- Items are numbered sequentially for easy reference