Initial settings service

Fastify API for storing third-party integration credentials (Newbook, Resos,
Nextcloud, Azure, SambaPOS) with AES-256-GCM encryption for sensitive fields.
Includes Newbook room sync endpoint and global_config store for shared app data.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -0,0 +1,10 @@
+services:
+  settings:
+    build: .
+    restart: unless-stopped
+    ports:
+      - "3080:3080"
+    environment:
+      DATABASE_URL: ${DATABASE_URL}
+      SETTINGS_SECRET: ${SETTINGS_SECRET}
+      AUTH_URL: ${AUTH_URL:-http://10.10.10.101:3001}