initial: canary multi-agent skills with tmux isolation support

- lib.sh: TMUX_SERVER_NAME env var, _tmux helper, shim externalized
  to TMPDIR with recursive guard, resolve_tmux_server helper for
  YAML-driven server routing
- multi-agent-create: --tmux-server opt-in flag, YAML tmux_server
  field for orphan prevention
- multi-agent-delete/resume/status/agent-sessions-monitor: use
  resolve_tmux_server to auto-route to correct isolated server
- SKILL.md × 4: documented isolation server workflow
- Verified by claude review (R1+re-run) + agy R2 patches
  (orphan prevention + shim location fix)

skills/multi-agent-resume/scripts/resolve_session_id.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# resolve_session_id.sh — multi-agent-resume 의 부속 스크립트
+# Usage:
+#   bash resolve_session_id.sh --workspace <path> --agent <claude|agy>
+# 출력: stdout 으로 UUID 한 줄 (없으면 빈 줄 + exit 0)
+#
+# P0-C: 전역 agent_identities 를 즉시 반환하지 않는다. lib.sh::find_workspace_uuid
+# 가 워크스페이스 격리된 해결 경로(per-row own id -> 디스크 스캔 -> cwd 일치하는
+# cache)만 사용. 다른 워크스페이스의 UUID 를 절대 반환하지 않음.
+set -euo pipefail
+
+source "$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)/lib.sh"
+
+usage() {
+  cat <<EOF
+Usage: $0 --workspace <path> --agent <claude|agy>
+Outputs the resolved UUID on stdout (empty if not found).
+EOF
+}
+
+WORKSPACE=""
+AGENT=""
+
+while [ $# -gt 0 ]; do
+  case "$1" in
+    --workspace) WORKSPACE="$2"; shift 2 ;;
+    --agent)     AGENT="$2";     shift 2 ;;
+    -h|--help)   usage; exit 0 ;;
+    *) echo "ERROR: unknown arg: $1" >&2; exit 2 ;;
+  esac
+done
+
+[ -n "$WORKSPACE" ] || { echo "ERROR: --workspace required" >&2; exit 2; }
+[ -n "$AGENT" ]    || { echo "ERROR: --agent required" >&2; exit 2; }
+case "$AGENT" in
+  claude|agy) ;;
+  *) echo "ERROR: --agent must be claude or agy" >&2; exit 2 ;;
+esac
+
+find_workspace_uuid "$WORKSPACE" "$AGENT"