refactor(blog): factory-style use cases + per-use-case controllers + getArticleBySlug

- Use cases (create-article, get-articles, get-article-by-slug NEW) → factory functions
- Controllers split: articles.controller.ts → 3 single-responsibility files
- DI module wires factories with .toDynamicValue()
- tRPC router resolves controllers via container

Refactor log: §2, §3, §4.1, §4.2, §5.1
Spec: §6.2

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/blog/src/di/container.test.ts

@@ -22,15 +22,18 @@ describe("blogContainer", () => {
     expect(repo).toBeInstanceOf(MockArticlesRepository);
   });
 
-  it("supports rebinding to a custom repo", () => {
-    blogContainer.unbind(BLOG_SYMBOLS.IArticlesRepository);
-    const custom = new MockArticlesRepository();
-    blogContainer
-      .bind<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository)
-      .toConstantValue(custom);
-    const resolved = blogContainer.get<IArticlesRepository>(
-      BLOG_SYMBOLS.IArticlesRepository,
-    );
-    expect(resolved).toBe(custom);
+  it("resolves IGetArticlesController from the container", () => {
+    const ctrl = blogContainer.get(BLOG_SYMBOLS.IGetArticlesController);
+    expect(typeof ctrl).toBe("function");
+  });
+
+  it("resolves ICreateArticleController from the container", () => {
+    const ctrl = blogContainer.get(BLOG_SYMBOLS.ICreateArticleController);
+    expect(typeof ctrl).toBe("function");
+  });
+
+  it("resolves IGetArticleBySlugController from the container", () => {
+    const ctrl = blogContainer.get(BLOG_SYMBOLS.IGetArticleBySlugController);
+    expect(typeof ctrl).toBe("function");
   });
 });

packages/blog/src/di/module.ts

@@ -2,10 +2,68 @@ import { ContainerModule, type interfaces } from "inversify";
 
 import type { IArticlesRepository } from "../application/repositories/articles.repository.interface";
 import { MockArticlesRepository } from "../infrastructure/repositories/articles.repository.mock";
+import {
+  getArticlesUseCase,
+  type IGetArticlesUseCase,
+} from "../application/use-cases/get-articles.use-case";
+import {
+  createArticleUseCase,
+  type ICreateArticleUseCase,
+} from "../application/use-cases/create-article.use-case";
+import {
+  getArticleBySlugUseCase,
+  type IGetArticleBySlugUseCase,
+} from "../application/use-cases/get-article-by-slug.use-case";
+import {
+  getArticlesController,
+  type IGetArticlesController,
+} from "../interface-adapters/controllers/get-articles.controller";
+import {
+  createArticleController,
+  type ICreateArticleController,
+} from "../interface-adapters/controllers/create-article.controller";
+import {
+  getArticleBySlugController,
+  type IGetArticleBySlugController,
+} from "../interface-adapters/controllers/get-article-by-slug.controller";
 import { BLOG_SYMBOLS } from "./symbols";
 
 export const BlogModule = new ContainerModule((bind: interfaces.Bind) => {
-  bind<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository).to(
-    MockArticlesRepository,
+  bind<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository).to(MockArticlesRepository);
+
+  bind<IGetArticlesUseCase>(BLOG_SYMBOLS.IGetArticlesUseCase).toDynamicValue((ctx) =>
+    getArticlesUseCase(
+      ctx.container.get<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository),
+    ),
+  );
+
+  bind<ICreateArticleUseCase>(BLOG_SYMBOLS.ICreateArticleUseCase).toDynamicValue((ctx) =>
+    createArticleUseCase(
+      ctx.container.get<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository),
+    ),
+  );
+
+  bind<IGetArticleBySlugUseCase>(BLOG_SYMBOLS.IGetArticleBySlugUseCase).toDynamicValue((ctx) =>
+    getArticleBySlugUseCase(
+      ctx.container.get<IArticlesRepository>(BLOG_SYMBOLS.IArticlesRepository),
+    ),
+  );
+
+  bind<IGetArticlesController>(BLOG_SYMBOLS.IGetArticlesController).toDynamicValue((ctx) =>
+    getArticlesController(
+      ctx.container.get<IGetArticlesUseCase>(BLOG_SYMBOLS.IGetArticlesUseCase),
+    ),
+  );
+
+  bind<ICreateArticleController>(BLOG_SYMBOLS.ICreateArticleController).toDynamicValue((ctx) =>
+    createArticleController(
+      ctx.container.get<ICreateArticleUseCase>(BLOG_SYMBOLS.ICreateArticleUseCase),
+    ),
+  );
+
+  bind<IGetArticleBySlugController>(BLOG_SYMBOLS.IGetArticleBySlugController).toDynamicValue((ctx) =>
+    getArticleBySlugController(
+      ctx.container.get<IGetArticleBySlugUseCase>(BLOG_SYMBOLS.IGetArticleBySlugUseCase),
+    ),
   );
 });

packages/blog/src/di/symbols.ts

@@ -1,3 +1,11 @@
 export const BLOG_SYMBOLS = {
   IArticlesRepository: Symbol.for("blog:IArticlesRepository"),
+  // Use cases
+  IGetArticlesUseCase: Symbol.for("blog:IGetArticlesUseCase"),
+  ICreateArticleUseCase: Symbol.for("blog:ICreateArticleUseCase"),
+  IGetArticleBySlugUseCase: Symbol.for("blog:IGetArticleBySlugUseCase"),
+  // Controllers
+  IGetArticlesController: Symbol.for("blog:IGetArticlesController"),
+  ICreateArticleController: Symbol.for("blog:ICreateArticleController"),
+  IGetArticleBySlugController: Symbol.for("blog:IGetArticleBySlugController"),
 } as const;