feat: add domains, ideas, layouts, widgets API modules

- Add DomainsModule with full CRUD, search, and activity logging
- Add IdeasModule with quick capture endpoint
- Add LayoutsModule for user dashboard layouts
- Add WidgetsModule for widget definitions (read-only)
- Update ActivityService with domain/idea logging methods
- Register all new modules in AppModule

apps/api/src/widgets/widgets.controller.ts

@@ -0,0 +1,39 @@
+import {
+  Controller,
+  Get,
+  Param,
+  UseGuards,
+} from "@nestjs/common";
+import { WidgetsService } from "./widgets.service";
+import { AuthGuard } from "../auth/guards/auth.guard";
+
+/**
+ * Controller for widget definition endpoints
+ * All endpoints require authentication
+ * Provides read-only access to available widget definitions
+ */
+@Controller("widgets")
+@UseGuards(AuthGuard)
+export class WidgetsController {
+  constructor(private readonly widgetsService: WidgetsService) {}
+
+  /**
+   * GET /api/widgets
+   * List all available widget definitions
+   * Returns only active widgets
+   */
+  @Get()
+  async findAll() {
+    return this.widgetsService.findAll();
+  }
+
+  /**
+   * GET /api/widgets/:name
+   * Get a widget definition by name
+   * Useful for fetching widget configuration schemas
+   */
+  @Get(":name")
+  async findByName(@Param("name") name: string) {
+    return this.widgetsService.findByName(name);
+  }
+}