feat: restructure backend with Elysia framework and add MQTT adapter

- Updated .gitignore to exclude generated files and database
- Modified package.json to change dev script and add new dependencies
- Removed src/index.ts and created app.ts for Elysia server initialization
- Added environment variable configuration in config/env.ts
- Implemented MQTT adapter in adapter/mqtt.ts for message handling
- Created Prisma client in prisma/client.ts and defined schema in prisma/schema.prisma
- Added seeding script in prisma/seed.ts for measurement points
- Established logging utility in utils/logger.ts for structured logging
- Created bed router in routes/bed.ts for handling bed-related routes

.env

@@ -0,0 +1,7 @@
+# Environment variables declared in this file are automatically made available to Prisma.
+# See the documentation for more detail: https://pris.ly/d/prisma-schema#accessing-environment-variables-from-the-schema
+
+# Prisma supports the native connection string format for PostgreSQL, MySQL, SQLite, SQL Server, MongoDB and CockroachDB.
+# See the documentation for all the connection string options: https://pris.ly/d/connection-strings
+
+DATABASE_URL="file:./data.db"