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/tenant-crypt.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+set -uo pipefail
+
+# CASAN Plan-16 SEC-23 (23.10, MT-02) — per-tenant encryption at rest (local-key MVP).
+#
+# Sensitive state (audit / telemetry) is encrypted with a PER-TENANT key so tenant B
+# — or an admin of B — cannot read tenant A's plaintext on disk. The key lives under
+# the tenant partition (0600) and differs per tenant, so a ciphertext produced by A
+# cannot be decrypted with B's key. Production form uses Vault Transit (23.11, needs
+# infra); this is the offline form.
+#
+# Usage:
+#   tenant-crypt.sh encrypt <plaintext-file> <ciphertext-file>
+#   tenant-crypt.sh decrypt <ciphertext-file> <plaintext-file>
+# Env: CASAN_TENANT_ID (key is tenant-specific; prod requires it — tenant-store).
+# Exit: 0 ok · 2 crypto failure (e.g. wrong tenant key) · 3 tenant/key/openssl error · 64 usage.
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+TS="$SCRIPT_DIR/tenant-store.sh"
+
+CMD="${1:-}"; IN="${2:-}"; OUT="${3:-}"
+command -v openssl >/dev/null 2>&1 || { echo "TENANT_CRYPT_OPENSSL_UNAVAILABLE" >&2; exit 3; }
+[[ -n "$CMD" && -n "$IN" && -n "$OUT" ]] || { echo "usage: tenant-crypt.sh {encrypt|decrypt} <in> <out>" >&2; exit 64; }
+[[ -f "$IN" ]] || { echo "TENANT_CRYPT_INPUT_MISSING file=$IN" >&2; exit 3; }
+
+# Per-tenant key (created once, 0600). tenant-store fails closed on an invalid/missing
+# tenant in prod; in dev it resolves under the 'default' tenant.
+KEYFILE="$(bash "$TS" resolve keys/at-rest.key 2>/dev/null)" || { echo "TENANT_CRYPT_DENIED (tenant unresolved)" >&2; exit 3; }
+if [[ ! -f "$KEYFILE" ]]; then
+  openssl rand -base64 48 > "$KEYFILE" 2>/dev/null || { echo "TENANT_CRYPT_KEYGEN_FAILED" >&2; exit 3; }
+  chmod 600 "$KEYFILE" 2>/dev/null || true
+fi
+
+case "$CMD" in
+  encrypt)
+    if openssl enc -aes-256-cbc -pbkdf2 -salt -in "$IN" -out "$OUT" -pass "file:$KEYFILE" 2>/dev/null; then
+      echo "TENANT_ENCRYPTED out=$OUT"
+      exit 0
+    fi
+    echo "TENANT_ENCRYPT_FAILED" >&2; exit 2
+    ;;
+  decrypt)
+    if openssl enc -d -aes-256-cbc -pbkdf2 -in "$IN" -out "$OUT" -pass "file:$KEYFILE" 2>/dev/null; then
+      echo "TENANT_DECRYPTED out=$OUT"
+      exit 0
+    fi
+    rm -f "$OUT" 2>/dev/null || true
+    echo "TENANT_DECRYPT_FAILED (wrong tenant key or corrupt ciphertext)" >&2; exit 2
+    ;;
+  *)
+    echo "Usage: tenant-crypt.sh {encrypt|decrypt} <in> <out>" >&2
+    exit 64
+    ;;
+esac