Phase 2 Week 5: Device Registration & Management

Implement device registration and management system for universal sync.

Database Changes:
- Add device queries to queries.sql (CRUD operations, registration, auth)
- Add sync queue management queries
- Add conflict resolution queries
- Regenerate sqlc models with new device-related types

Device Handler (devices.go):
- InitiateRegistration: Start device registration with auth URL and QR code
- CheckRegistrationStatus: Poll for registration approval
- ListDevices: Get all devices for current user
- GetDevice: Get specific device details
- UpdateDevice: Update device settings (name, sync settings, frequency)
- DeleteDevice: Remove device from account
- ApproveDevice: User approves device registration via web
- RejectDevice: Reject pending device registration
- ListPendingRegistrations: Show all pending registrations
- generateDeviceToken: Generate secure Bearer token for devices

Device Authentication Middleware (device_auth.go):
- Authenticate: Validate device Bearer tokens
- RequirePermission: Check device permissions by type
- hasPermission: Define permissions per device type
- UpdateLastSeen: Auto-update device last_seen timestamp

Configuration:
- Add BaseURL field to Config for device setup URLs

API Endpoints:
POST /api/devices/register - Initiate device registration
POST /api/devices/register/status - Check registration status
GET /api/devices/approve/:id - Approve device (web UI)
POST /api/devices/reject/:id - Reject device
GET /api/devices - List user's devices
GET /api/devices/:id - Get device details
PUT /api/devices/:id - Update device settings
DELETE /api/devices/:id - Delete device
GET /api/devices/pending - List pending registrations

Bruno API Collection:
- Initiate Device Registration
- Check Registration Status
- List Devices
- Get Device
- Update Device
- Delete Device

Dependencies:
- github.com/skip2/go-qrcode for QR code generation

Device Types Supported:
- koreader: Calibre-compatible sync
- kobo: Kobo sync protocol
- web: Web interface
- mobile: Mobile apps

Device Permissions:
- sync:progress
- sync:annotations
- sync:metadata
- device:manage (web only)

internal/config/config.go

@@ -8,6 +8,7 @@ import (
 
 type Config struct {
 	ServerPort        string
+	BaseURL           string
 	JWTSecret         string
 	UploadPath        string
 	DatabaseHost      string
@@ -23,6 +24,7 @@ type Config struct {
 func LoadConfig() *Config {
 	return &Config{
 		ServerPort:        getEnv("SERVER_PORT", "8080"),
+		BaseURL:           getEnv("BASE_URL", "http://localhost:8080"),
 		DatabaseHost:      getEnv("DATABASE_HOST", "localhost"),
 		DatabasePort:      getEnv("DATABASE_PORT", "5432"),
 		DatabaseUser:      getEnv("DATABASE_USER", "postgres"),