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/domains/dto/create-domain.dto.ts

@@ -0,0 +1,47 @@
+import {
+  IsString,
+  IsOptional,
+  MinLength,
+  MaxLength,
+  Matches,
+  IsObject,
+} from "class-validator";
+
+/**
+ * DTO for creating a new domain
+ */
+export class CreateDomainDto {
+  @IsString({ message: "name must be a string" })
+  @MinLength(1, { message: "name must not be empty" })
+  @MaxLength(255, { message: "name must not exceed 255 characters" })
+  name!: string;
+
+  @IsString({ message: "slug must be a string" })
+  @MinLength(1, { message: "slug must not be empty" })
+  @MaxLength(100, { message: "slug must not exceed 100 characters" })
+  @Matches(/^[a-z0-9-]+$/, {
+    message: "slug must contain only lowercase letters, numbers, and hyphens",
+  })
+  slug!: string;
+
+  @IsOptional()
+  @IsString({ message: "description must be a string" })
+  @MaxLength(10000, { message: "description must not exceed 10000 characters" })
+  description?: string;
+
+  @IsOptional()
+  @IsString({ message: "color must be a string" })
+  @Matches(/^#[0-9A-F]{6}$/i, {
+    message: "color must be a valid hex color code (e.g., #FF5733)",
+  })
+  color?: string;
+
+  @IsOptional()
+  @IsString({ message: "icon must be a string" })
+  @MaxLength(50, { message: "icon must not exceed 50 characters" })
+  icon?: string;
+
+  @IsOptional()
+  @IsObject({ message: "metadata must be an object" })
+  metadata?: Record<string, unknown>;
+}

apps/api/src/domains/dto/index.ts

@@ -0,0 +1,3 @@
+export { CreateDomainDto } from "./create-domain.dto";
+export { UpdateDomainDto } from "./update-domain.dto";
+export { QueryDomainsDto } from "./query-domains.dto";

apps/api/src/domains/dto/query-domains.dto.ts

@@ -0,0 +1,34 @@
+import {
+  IsUUID,
+  IsOptional,
+  IsInt,
+  Min,
+  Max,
+  IsString,
+} from "class-validator";
+import { Type } from "class-transformer";
+
+/**
+ * DTO for querying domains with filters and pagination
+ */
+export class QueryDomainsDto {
+  @IsUUID("4", { message: "workspaceId must be a valid UUID" })
+  workspaceId!: string;
+
+  @IsOptional()
+  @IsString({ message: "search must be a string" })
+  search?: string;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt({ message: "page must be an integer" })
+  @Min(1, { message: "page must be at least 1" })
+  page?: number;
+
+  @IsOptional()
+  @Type(() => Number)
+  @IsInt({ message: "limit must be an integer" })
+  @Min(1, { message: "limit must be at least 1" })
+  @Max(100, { message: "limit must not exceed 100" })
+  limit?: number;
+}

apps/api/src/domains/dto/update-domain.dto.ts

@@ -0,0 +1,50 @@
+import {
+  IsString,
+  IsOptional,
+  MinLength,
+  MaxLength,
+  Matches,
+  IsObject,
+} from "class-validator";
+
+/**
+ * DTO for updating an existing domain
+ * All fields are optional to support partial updates
+ */
+export class UpdateDomainDto {
+  @IsOptional()
+  @IsString({ message: "name must be a string" })
+  @MinLength(1, { message: "name must not be empty" })
+  @MaxLength(255, { message: "name must not exceed 255 characters" })
+  name?: string;
+
+  @IsOptional()
+  @IsString({ message: "slug must be a string" })
+  @MinLength(1, { message: "slug must not be empty" })
+  @MaxLength(100, { message: "slug must not exceed 100 characters" })
+  @Matches(/^[a-z0-9-]+$/, {
+    message: "slug must contain only lowercase letters, numbers, and hyphens",
+  })
+  slug?: string;
+
+  @IsOptional()
+  @IsString({ message: "description must be a string" })
+  @MaxLength(10000, { message: "description must not exceed 10000 characters" })
+  description?: string | null;
+
+  @IsOptional()
+  @IsString({ message: "color must be a string" })
+  @Matches(/^#[0-9A-F]{6}$/i, {
+    message: "color must be a valid hex color code (e.g., #FF5733)",
+  })
+  color?: string | null;
+
+  @IsOptional()
+  @IsString({ message: "icon must be a string" })
+  @MaxLength(50, { message: "icon must not exceed 50 characters" })
+  icon?: string | null;
+
+  @IsOptional()
+  @IsObject({ message: "metadata must be an object" })
+  metadata?: Record<string, unknown>;
+}