Improve startup resilience and add debug logging

- Reduce database retry count and backoff time
- Make SECRET_KEY optional (use default with warning)
- Add config debug logging on startup
- Remove strict validation that prevented startup

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

cmd/api/main.go

@@ -33,17 +33,22 @@ func main() {
 	log.Info().
 		Bool("debug", cfg.Server.Debug).
 		Int("port", cfg.Server.Port).
+		Str("db_host", cfg.Database.Host).
+		Int("db_port", cfg.Database.Port).
+		Str("db_name", cfg.Database.Database).
+		Str("db_user", cfg.Database.User).
+		Str("redis_url", cfg.Redis.URL).
 		Msg("Starting MyCrib API server")
 
-	// Connect to database (retry with backoff)
+	// Connect to database (retry with shorter backoff for container health checks)
 	var db *gorm.DB
-	for i := 0; i < 5; i++ {
+	for i := 0; i < 3; i++ {
 		db, err = database.Connect(&cfg.Database, cfg.Server.Debug)
 		if err == nil {
 			break
 		}
 		log.Warn().Err(err).Int("attempt", i+1).Msg("Failed to connect to database, retrying...")
-		time.Sleep(time.Duration(i+1) * 2 * time.Second)
+		time.Sleep(time.Duration(i+1) * time.Second)
 	}
 	if err != nil {
 		log.Fatal().Err(err).Msg("Failed to connect to database after retries")