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

prisma/schema.prisma

@@ -0,0 +1,81 @@
+// This is your Prisma schema file,
+// learn more about it in the docs: https://pris.ly/d/prisma-schema
+
+generator client {
+  provider = "prisma-client-js"
+  output   = "../generated/prisma"
+}
+
+datasource db {
+  provider = "sqlite"
+  url      = env("DATABASE_URL")
+}
+
+model MeasurementPoint {
+  id                String @id @default(cuid())
+  sensorId          String @unique // e.g., "head-1", "back-2"
+  label             String // e.g., "Head Left", "Upper Back Center"
+  zone              String // e.g., "head", "back", "shoulders"
+  x                 Int    // X coordinate on bed layout
+  y                 Int    // Y coordinate on bed layout
+  pin               Int   // Hardware pin number
+  
+  // Threshold configuration
+  warningThreshold  Int    // Pressure value that triggers warning
+  alarmThreshold    Int    // Pressure value that triggers alarm
+  warningDelayMs    Int    // Delay before warning escalates to alarm
+  
+  // Timestamps
+  createdAt         DateTime @default(now())
+  updatedAt         DateTime @updatedAt
+  
+  // Relations
+  data              MeasurementPointData[]
+  alerts            Alert[]
+}
+
+model MeasurementPointData {
+  id                String @id @default(cuid())
+  measurementPointId String
+  
+  // Sensor reading data
+  value             Int      // Analog sensor value (0-4095)
+  
+  // Timestamps
+  timestamp         DateTime @default(now())
+  time              String   // Formatted time string
+  
+  // Relations
+  measurementPoint  MeasurementPoint @relation(fields: [measurementPointId], references: [id], onDelete: Cascade)
+  
+  @@index([measurementPointId, timestamp])
+}
+
+enum AlertType {
+  WARNING
+  ALARM
+}
+
+model Alert {
+  id                String @id @default(cuid())
+  measurementPointId String
+  
+  // Alert details
+  type              AlertType
+  value             Int      // Sensor value that triggered alert
+  threshold         Int      // Threshold that was exceeded
+  
+  // Alert state
+  acknowledged      Boolean @default(false)
+  silenced          Boolean @default(false)
+  
+  // Timing
+  startTime         DateTime @default(now())
+  endTime           DateTime?
+  
+  // Relations
+  measurementPoint  MeasurementPoint @relation(fields: [measurementPointId], references: [id], onDelete: Cascade)
+  
+  @@index([measurementPointId, startTime])
+  @@index([type, acknowledged])
+}