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/scripts/bash/provider-cost-lookup.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+"""Return '<total_tokens> <cost_usd>' for the provider-telemetry record that
+matches the given step, or print nothing if there is no genuine match.
+
+Never falls back to an arbitrary record — reusing one sample's cost across
+every step would misrepresent an estimate as real per-step billing.
+
+Usage: provider-cost-lookup.py <provider-usage.jsonl> <step-name>
+"""
+import json
+import sys
+
+if len(sys.argv) < 3:
+    sys.exit(0)
+path, step = sys.argv[1], sys.argv[2]
+match = None
+try:
+    with open(path, encoding="utf-8") as fh:
+        for line in fh:
+            line = line.strip()
+            if not line:
+                continue
+            rec = json.loads(line)
+            if rec.get("step") == step:
+                match = rec  # last matching record wins
+except OSError:
+    sys.exit(0)
+if match is not None:
+    print(f"{match.get('total_tokens', 0)} {match.get('cost_usd', 0)}")