Add SQLite database for dynamic guild management

Features:
- SQLite database with better-sqlite3 for guild configurations
- Auto-registration when bot joins new guilds with welcome messages
- Soft delete system preserves settings when bot is removed
- Dynamic configuration via /config slash command with subcommands
- Automatic migration from config.json to database on first run
- Support for scheduled events with timezone preservation

Technical Implementation:
- Node.js 20 for better SQLite compatibility in Docker
- Full Debian base image with npm for reliable native module compilation
- Database persistence via Docker volume (./data)
- Hybrid configuration system (database primary, file fallback)
- JSON storage for complex schedule objects with timezone support

Database Schema:
- guilds table with soft delete (is_active flag)
- scheduled_events table with JSON schedule storage
- bot_config table for global settings
- Auto-initialization and seeding from existing config

Admin Features:
- /config show - View current server settings
- /config subcommands - Update prefix, volume, features, etc.
- Administrator permissions required for configuration changes
- Graceful handling of missing or malformed data

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

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

.gitignore

@@ -49,6 +49,7 @@ Temporary Items
 # Ignores
 node_modules
 logs
+data/
 
 start.bat
 tokens.json