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/sandbox-container.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+set -uo pipefail
+
+# CASAN Track C — TRUE runtime isolation via container (C6 / V22, production form).
+#
+# Upgrades the static-policy scaffold (sandbox-run.sh) to real kernel isolation:
+# the command runs inside a locked-down container where the KERNEL — not a grep —
+# neutralises escapes:
+#   --network=none   → no egress at all
+#   --read-only      → root filesystem is immutable (can't write outside workspace)
+#   --pids-limit     → fork bombs are capped
+#   --memory/--cpus  → resource abuse is bounded
+#   -v <ws>:/work:rw → ONLY the workspace is writable; host $HOME/.ssh is NOT mounted
+#   --cap-drop=ALL --security-opt=no-new-privileges → no privilege escalation
+#
+# Usage:
+#   sandbox-container.sh --workspace <dir> [--image busybox] [--timeout 20]
+#                        [--memory 256m] [--pids 128] [--cpus 1] -- <command...>
+# Exit: command's exit code · 124 timeout · 2 policy/setup error · 127 no docker.
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+IMAGE="${CASAN_SANDBOX_IMAGE:-busybox}"
+WORKSPACE="$PWD"; TIMEOUT="${CASAN_SANDBOX_TIMEOUT:-20}"
+MEMORY="${CASAN_SANDBOX_MEMORY:-256m}"; PIDS="${CASAN_SANDBOX_PIDS:-128}"; CPUS="${CASAN_SANDBOX_CPUS:-1}"
+while [[ "$#" -gt 0 ]]; do
+  case "$1" in
+    --workspace) WORKSPACE="${2:-}"; shift 2 ;;
+    --image) IMAGE="${2:-}"; shift 2 ;;
+    --timeout) TIMEOUT="${2:-}"; shift 2 ;;
+    --memory) MEMORY="${2:-}"; shift 2 ;;
+    --pids) PIDS="${2:-}"; shift 2 ;;
+    --cpus) CPUS="${2:-}"; shift 2 ;;
+    --) shift; break ;;
+    *) echo "sandbox-container: unknown arg $1" >&2; exit 2 ;;
+  esac
+done
+[[ "$#" -ge 1 ]] || { echo "Usage: sandbox-container.sh --workspace <dir> -- <command...>" >&2; exit 2; }
+
+command -v docker >/dev/null 2>&1 || { echo "SANDBOX_CONTAINER_NO_DOCKER" >&2; exit 127; }
+docker info >/dev/null 2>&1 || { echo "SANDBOX_CONTAINER_DOCKER_DOWN" >&2; exit 127; }
+
+WS_ABS="$(cd "$WORKSPACE" 2>/dev/null && pwd)" || { echo "SANDBOX_CONTAINER_BAD_WORKSPACE" >&2; exit 2; }
+
+# Join the command into a single shell string to run inside the container.
+CMD="$*"
+
+# Hardened container. --init reaps zombies; tmpfs gives a small writable /tmp
+# without a writable rootfs. The wall-clock timeout goes through tool-exec.sh
+# (portable: `timeout` if present, else a perl alarm — macOS has no coreutils
+# `timeout`). Container name is tracked so a timed-out container is force-removed.
+CID="casan-sbx-$$-${RANDOM}"
+set +e
+bash "$SCRIPT_DIR/tool-exec.sh" "$TIMEOUT" -- \
+  docker run --rm --init --name "$CID" \
+    --network=none --read-only \
+    --pids-limit="$PIDS" --memory="$MEMORY" --cpus="$CPUS" \
+    --cap-drop=ALL --security-opt=no-new-privileges \
+    --tmpfs /tmp:rw,size=16m \
+    -v "$WS_ABS":/work:rw -w /work \
+    "$IMAGE" sh -c "$CMD"
+rc=$?
+set -e
+if [[ "$rc" -eq 124 ]]; then
+  docker rm -f "$CID" >/dev/null 2>&1 || true
+  echo "SANDBOX_CONTAINER_TIMEOUT after ${TIMEOUT}s" >&2
+  exit 124
+fi
+exit "$rc"