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/server/src/routes/pipeline/index.ts

@@ -0,0 +1,77 @@
+/**
+ * Pipeline routes - HTTP API for pipeline configuration management
+ *
+ * Provides endpoints for:
+ * - Getting pipeline configuration
+ * - Saving pipeline configuration
+ * - Adding, updating, deleting, and reordering pipeline steps
+ *
+ * All endpoints use handler factories that receive the PipelineService instance.
+ * Mounted at /api/pipeline in the main server.
+ */
+
+import { Router } from 'express';
+import type { PipelineService } from '../../services/pipeline-service.js';
+import { validatePathParams } from '../../middleware/validate-paths.js';
+import { createGetConfigHandler } from './routes/get-config.js';
+import { createSaveConfigHandler } from './routes/save-config.js';
+import { createAddStepHandler } from './routes/add-step.js';
+import { createUpdateStepHandler } from './routes/update-step.js';
+import { createDeleteStepHandler } from './routes/delete-step.js';
+import { createReorderStepsHandler } from './routes/reorder-steps.js';
+
+/**
+ * Create pipeline router with all endpoints
+ *
+ * Endpoints:
+ * - POST /config - Get pipeline configuration
+ * - POST /config/save - Save entire pipeline configuration
+ * - POST /steps/add - Add a new pipeline step
+ * - POST /steps/update - Update an existing pipeline step
+ * - POST /steps/delete - Delete a pipeline step
+ * - POST /steps/reorder - Reorder pipeline steps
+ *
+ * @param pipelineService - Instance of PipelineService for file I/O
+ * @returns Express Router configured with all pipeline endpoints
+ */
+export function createPipelineRoutes(pipelineService: PipelineService): Router {
+  const router = Router();
+
+  // Get pipeline configuration
+  router.post(
+    '/config',
+    validatePathParams('projectPath'),
+    createGetConfigHandler(pipelineService)
+  );
+
+  // Save entire pipeline configuration
+  router.post(
+    '/config/save',
+    validatePathParams('projectPath'),
+    createSaveConfigHandler(pipelineService)
+  );
+
+  // Pipeline step operations
+  router.post(
+    '/steps/add',
+    validatePathParams('projectPath'),
+    createAddStepHandler(pipelineService)
+  );
+  router.post(
+    '/steps/update',
+    validatePathParams('projectPath'),
+    createUpdateStepHandler(pipelineService)
+  );
+  router.post(
+    '/steps/delete',
+    validatePathParams('projectPath'),
+    createDeleteStepHandler(pipelineService)
+  );
+  router.post(
+    '/steps/reorder',
+    validatePathParams('projectPath'),
+    createReorderStepsHandler(pipelineService)
+  );
+
+  return router;
+}