feat: Add SQLite database support and fixed portable extraction path

- Add SQLite as alternative database for offline/firewall environments
- Add --database-type parameter to build-client.bat (mysql/sqlite)
- Refactor database.py to support both MySQL and SQLite
- Add DB_TYPE and SQLITE_PATH configuration options
- Set fixed unpackDirName for portable exe (Meeting-Assistant)
- Update DEPLOYMENT.md with SQLite mode documentation

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

client/package.json

@@ -72,7 +72,8 @@
       "icon": "assets/icon.png"
     },
     "portable": {
-      "artifactName": "${productName}-${version}-portable.${ext}"
+      "artifactName": "${productName}-${version}-portable.${ext}",
+      "unpackDirName": "Meeting-Assistant"
     }
   }
 }