Fix MQTT password sync to actually update password.txt

- Add scripts/sync-mqtt-config.ts for standalone sync execution
- Update change-mqtt-admin-password.sh to use tsx to execute sync
- Now properly regenerates password.txt with new hashed password
- Mosquitto config is automatically reloaded after sync

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/sync-mqtt-config.ts

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+/**
+ * Standalone script to sync MQTT configuration
+ * This can be run directly without authentication
+ */
+
+import { syncMosquittoConfig } from '../lib/mosquitto-sync';
+
+async function main() {
+  try {
+    console.log('Starting MQTT configuration sync...');
+    const result = await syncMosquittoConfig();
+
+    if (result.success) {
+      console.log('✓ Success:', result.message);
+      process.exit(0);
+    } else {
+      console.error('✗ Failed:', result.message);
+      process.exit(1);
+    }
+  } catch (error) {
+    console.error('✗ Error:', error instanceof Error ? error.message : String(error));
+    process.exit(1);
+  }
+}
+
+main();