feat: implement pipeline feature for automated workflow steps

- Introduced a new pipeline service to manage custom workflow steps that execute after a feature is marked "In Progress".
- Added API endpoints for configuring, saving, adding, updating, deleting, and reordering pipeline steps.
- Enhanced the UI to support pipeline settings, including a dialog for managing steps and integration with the Kanban board.
- Updated the application state management to handle pipeline configurations per project.
- Implemented dynamic column generation in the Kanban board to display pipeline steps between "In Progress" and "Waiting Approval".
- Added documentation for the new pipeline feature, including usage instructions and configuration details.

This feature allows for a more structured workflow, enabling automated processes such as code reviews and testing after feature implementation.

apps/ui/src/components/views/board-view/hooks/use-board-features.ts

@@ -203,6 +203,11 @@ export function useBoardFeatures({ currentProject }: UseBoardFeaturesProps) {
         // This ensures the feature card shows the "Approve Plan" button
         console.log('[Board] Plan approval required, reloading features...');
         loadFeatures();
+      } else if (event.type === 'pipeline_step_started') {
+        // Pipeline steps update the feature status to `pipeline_*` before the step runs.
+        // Reload so the card moves into the correct pipeline column immediately.
+        console.log('[Board] Pipeline step started, reloading features...');
+        loadFeatures();
       } else if (event.type === 'auto_mode_error') {
         // Reload features when an error occurs (feature moved to waiting_approval)
         console.log('[Board] Feature error, reloading features...', event.error);