Add TCP/UDP port mapping support

- Add app_ports table for storing port mappings per app
- Add Port model with CRUD operations
- Add handlers for adding/deleting port mappings
- Add ports section to app detail template
- Update Docker client to configure port bindings when creating containers
- Support both TCP and UDP protocols

internal/models/app.go

@@ -96,6 +96,11 @@ func (a *App) GetVolumes(ctx context.Context) ([]*Volume, error) {
 	return FindVolumesByAppID(ctx, a.db, a.ID)
 }
 
+// GetPorts returns all port mappings for this app.
+func (a *App) GetPorts(ctx context.Context) ([]*Port, error) {
+	return FindPortsByAppID(ctx, a.db, a.ID)
+}
+
 // GetDeployments returns recent deployments for this app.
 func (a *App) GetDeployments(ctx context.Context, limit int) ([]*Deployment, error) {
 	return FindDeploymentsByAppID(ctx, a.db, a.ID, limit)