Add webhook logging, pagination, middleware, migrations, and prod hardening

- Webhook event logging repo and subscription webhook idempotency
- Pagination helper (echohelpers) with cursor/offset support
- Request ID and structured logging middleware
- Push client improvements (FCM HTTP v1, better error handling)
- Task model version column, business constraint migrations, targeted indexes
- Expanded categorization chain tests
- Email service and config hardening
- CI workflow updates, .gitignore additions, .env.example updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/database/database.go

@@ -13,22 +13,38 @@ import (
 	"github.com/treytartt/casera-api/internal/models"
 )
 
+// zerologGormWriter adapts zerolog for GORM's logger interface
+type zerologGormWriter struct{}
+
+func (w zerologGormWriter) Printf(format string, args ...interface{}) {
+	log.Warn().Msgf(format, args...)
+}
+
 var db *gorm.DB
 
 // Connect establishes a connection to the PostgreSQL database
 func Connect(cfg *config.DatabaseConfig, debug bool) (*gorm.DB, error) {
-	// Configure GORM logger
+	// Configure GORM logger with slow query detection
 	logLevel := logger.Silent
 	if debug {
 		logLevel = logger.Info
 	}
 
+	gormLogger := logger.New(
+		zerologGormWriter{},
+		logger.Config{
+			SlowThreshold:             200 * time.Millisecond,
+			LogLevel:                  logLevel,
+			IgnoreRecordNotFoundError: true,
+		},
+	)
+
 	gormConfig := &gorm.Config{
-		Logger: logger.Default.LogMode(logLevel),
+		Logger: gormLogger,
 		NowFunc: func() time.Time {
 			return time.Now().UTC()
 		},
-		PrepareStmt: true, // Cache prepared statements
+		PrepareStmt: true,
 	}
 
 	// Connect to database