feat(plan-01): Phase 1 — relocate harness code to packages/casan-harness (symlink facade)

Physically move the pure-code subtrees out of .specify into the package, leaving
compat symlinks at the old .specify/<dir> paths so every existing reference (internal
CASAN_HARNESS_ROOT + external CI/docker/mjs) keeps resolving. Runtime state stays put.

Moved (git mv): scripts/ tests/ security/ templates/ config/ governance/ memory/
  .specify/<dir>  ->  packages/casan-harness/<dir>   (+ .specify/<dir> symlink)
Stays in .specify (state/governance/domain, handled later): logs/ agentops/ level5/
  init-options.json traceability-map.json

Python `.resolve()` self-location followed the compat symlink into packages and lost
the app root; generate-casan-demo-context.py, generate-agentops-dashboard.py and
dashboard-server.py now walk UP for the `.specify` state marker instead of a fixed
parent depth (fixes "missing trace files" in run-casan4).

Full gate: PASS=64 FAIL=0 SKIP=3 (CASAN_CI_STEP_TIMEOUT_SEC=1200 — track-a ~450s runs
close to the 600s default and can tip over under load; this is timing variance, not a
regression — it passed cleanly with headroom). Runtime log/audit artifacts kept unstaged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

AINative_OKR_CASAN5/packages/casan-harness/scripts/bash/model-fallback.sh

@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# CASAN Level 5 fallback runner.
+# Usage:
+#   model-fallback.sh <output-file> --primary '<cmd>' --fallback '<cmd>'
+
+OUTPUT_FILE="${1:-}"
+shift || true
+
+PRIMARY_CMD=""
+FALLBACK_CMD=""
+
+while [[ "$#" -gt 0 ]]; do
+  case "$1" in
+    --primary)
+      PRIMARY_CMD="${2:-}"
+      shift 2
+      ;;
+    --fallback)
+      FALLBACK_CMD="${2:-}"
+      shift 2
+      ;;
+    *)
+      echo "Unknown argument: $1" >&2
+      exit 64
+      ;;
+  esac
+done
+
+if [[ -z "$OUTPUT_FILE" || -z "$PRIMARY_CMD" || -z "$FALLBACK_CMD" ]]; then
+  echo "Usage: model-fallback.sh <output-file> --primary '<cmd>' --fallback '<cmd>'" >&2
+  exit 64
+fi
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/casan-paths.sh"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
+LOG_DIR="$CASAN_STATE_ROOT/logs/level5"
+mkdir -p "$LOG_DIR" "$(dirname "$OUTPUT_FILE")"
+FALLBACK_LOG="$LOG_DIR/fallback.jsonl"
+TRACE_ID="$(uuidgen 2>/dev/null | tr '[:upper:]' '[:lower:]' || printf 'fallback-%s-%s' "$(date +%s)" "$$")"
+TIMESTAMP="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"
+
+TMP_PRIMARY="$(mktemp)"
+TMP_FALLBACK="$(mktemp)"
+
+set +e
+bash -c "$PRIMARY_CMD" > "$TMP_PRIMARY" 2>&1
+PRIMARY_RC=$?
+set -e
+
+ROUTE="primary"
+FINAL_RC="$PRIMARY_RC"
+if [[ "$PRIMARY_RC" -eq 0 && -s "$TMP_PRIMARY" ]]; then
+  cp "$TMP_PRIMARY" "$OUTPUT_FILE"
+else
+  ROUTE="fallback"
+  set +e
+  bash -c "$FALLBACK_CMD" > "$TMP_FALLBACK" 2>&1
+  FALLBACK_RC=$?
+  set -e
+  FINAL_RC="$FALLBACK_RC"
+  cp "$TMP_FALLBACK" "$OUTPUT_FILE"
+fi
+
+printf '{"timestamp":"%s","trace_id":"%s","harness":"L5-model-fallback","primary_exit":%s,"route":"%s","final_exit":%s,"output":"%s"}\n' \
+  "$TIMESTAMP" "$TRACE_ID" "$PRIMARY_RC" "$ROUTE" "$FINAL_RC" "$OUTPUT_FILE" >> "$FALLBACK_LOG"
+
+echo "FALLBACK_ROUTE route=$ROUTE primary_exit=$PRIMARY_RC final_exit=$FINAL_RC output=$OUTPUT_FILE"
+exit "$FINAL_RC"