feat: Implement core backend infrastructure including configuration management, SQLite database with team owners and app settings, and initial owner-related APIs and frontend components.

backend/internal/config/config.go

@@ -174,6 +174,9 @@ func InitFromDB() *Config {
 			cfg.MailServices = services
 		}
 	}
+	if v, _ := configDB.GetConfig("site_name"); v != "" {
+		cfg.SiteName = v
+	}
 
 	Global = cfg
 	return cfg
@@ -210,6 +213,10 @@ func SaveToDB() error {
 		configDB.SetConfig("mail_services", string(data))
 	}
 
+	if cfg.SiteName != "" {
+		configDB.SetConfig("site_name", cfg.SiteName)
+	}
+
 	return nil
 }