feat: Implement layer CRUD API endpoints with RBAC

backend/src/routes/layers.ts

@@ -1,5 +1,31 @@
 import { FastifyInstance } from 'fastify';
+import { authenticate, authorizeProjectMember, authorizePlannerPlus } from '../middleware/auth';
+import { getLayers, createLayer, updateLayer, deleteLayer, reorderLayers } from '../controllers/layerController';
+import { validateLayerCreation, validateLayerUpdate, validateLayerReorder } from '../validators/layerValidator';
 
 export default async function layersRoutes(fastify: FastifyInstance) {
-  // Placeholder for layers routes
+  // GET /projects/:projectId/layers - List layers for project
+  fastify.get('/', {
+    preHandler: [authenticate, authorizeProjectMember]
+  }, getLayers);
+
+  // POST /projects/:projectId/layers/ - Create layer (Planner+)
+  fastify.post('/', {
+    preHandler: [authenticate, authorizeProjectMember, authorizePlannerPlus]
+  }, createLayer);
+
+  // PUT /projects/:projectId/layers/:layerId - Update layer (Planner+)
+  fastify.put('/:layerId', {
+    preHandler: [authenticate, authorizeProjectMember, authorizePlannerPlus]
+  }, updateLayer);
+
+  // DELETE /projects/:projectId/layers/:layerId - Delete layer (Planner+)
+  fastify.delete('/:layerId', {
+    preHandler: [authenticate, authorizeProjectMember, authorizePlannerPlus]
+  }, deleteLayer);
+
+  // PUT /projects/:projectId/layers/reorder - Reorder layers (Planner+)
+  fastify.put('/reorder', {
+    preHandler: [authenticate, authorizeProjectMember, authorizePlannerPlus]
+  }, reorderLayers);
 }