chore: add mission infrastructure for execution loop validation system

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

.factory/init.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Mission init script — idempotent environment setup
+# Runs at the start of each worker session
+
+MISSION_ROOT="$(git -C "$(dirname "$0")" rev-parse --show-toplevel 2>/dev/null || echo "$(dirname "$0")/../..")"
+
+echo "[init] Mission: Enhance Mission Execution Loop"
+echo "[init] Root: $MISSION_ROOT"
+
+# Ensure dependencies are installed
+if [ ! -d "$MISSION_ROOT/node_modules" ]; then
+  echo "[init] Installing dependencies..."
+  cd "$MISSION_ROOT" && pnpm install --frozen-lockfile
+else
+  echo "[init] Dependencies already installed."
+fi
+
+echo "[init] Environment ready."