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/governance/approval-flow.yaml

@@ -0,0 +1,95 @@
+version: 1.0
+description: AI Governance Approval Workflow
+
+workflow:
+
+  name: casan_level4_agent_action_approval
+
+  steps:
+
+    - id: STEP-001
+      name: Submit Prompt
+      actor: developer
+      action: submit_prompt
+      output: prompt_received
+
+    - id: STEP-002
+      name: Security Validation
+      actor: system
+      action: validate_security
+      input: prompt_received
+      output: security_checked
+      fail_action: block
+
+    - id: STEP-003
+      name: Risk Assessment
+      actor: system
+      action: evaluate_risk
+      input: security_checked
+      output: risk_level
+
+    - id: STEP-004
+      name: Approval Decision
+      actor: architect
+      condition:
+        - if: risk_level == "high"
+          action: require_approval
+        - if: risk_level == "medium"
+          action: optional_approval
+        - if: risk_level == "low"
+          action: auto_approve
+
+    - id: STEP-005
+      name: LLM Execution
+      actor: system
+      condition: approved == true
+      action: call_llm
+      output: response
+
+    - id: STEP-006
+      name: Audit Logging
+      actor: system
+      action: log_event
+      input: all
+      output: audit_record
+
+approval_roles:
+
+  developer:
+    can_submit: true
+    can_approve: false
+
+  architect:
+    can_submit: false
+    can_approve: true
+
+  system:
+    can_execute: true
+
+rules:
+
+  high_risk:
+    required_approver: architect
+    timeout: 10m
+    default_decision: deny
+    non_interactive_override:
+      env_decision: CASAN_APPROVAL_DECISION
+      env_approver: CASAN_APPROVER
+
+  medium_risk:
+    required_approver: optional
+    timeout: 5m
+    default_decision: auto_approve_with_audit
+
+  low_risk:
+    auto_approve: true
+
+notifications:
+
+  on_approval_required:
+    channel: log
+    message: "Approval required for high-risk action"
+
+  on_denied:
+    channel: log
+    message: "Request denied"