refactor: migrate from better-sqlite3 to Prisma (#170)

* refactor: migrate from better-sqlite3 to Prisma

- Install Prisma dependencies and initialize with SQLite
- Create Prisma schema matching existing database structure
- Replace database.js with Prisma-based database service
- Update all API routes, tRPC routers, and WebSocket handler
- Convert TypeScript types to match Prisma schema
- Update build process to include Prisma migrations
- Remove better-sqlite3 dependency

All database operations now use Prisma while maintaining SQLite backend.

* fix: flatten server data in installed scripts API responses

- Transform Prisma nested server objects to flattened fields expected by frontend
- Update getAllInstalledScripts, getInstalledScriptsByServer, and getInstalledScriptById
- Server names should now display correctly in the installed scripts table
- Use nullish coalescing operators for better null handling

* fix: ensure DATABASE_URL is set in .env for Prisma during updates

- Add ensure_database_url() function to update.sh
- Function checks if .env exists and creates from .env.example if needed
- Automatically adds DATABASE_URL if not present
- Call function after restore_backup_files() in update flow
- Fixes Prisma client generation error during updates

Author: michelroegl-brunner

.gitignore

@@ -49,4 +49,5 @@ yarn-error.log*
 *.tsbuildinfo
 
 # idea files
-.idea
+.idea
+/generated/prisma