refactor(features): rename mock/payload/interface files per Lazar pattern

Convention now: <name>.repository.{ts,mock.ts,interface.ts}.
Renames .mock prefix to .mock suffix; drops .payload prefix from real
impls (canonical name = real impl); dot-separates the .repository
qualifier in interface filenames. Class names follow suit:
PayloadXRepository → XRepository; Mock* unchanged.

Refactor log: §1, §3
Spec: §9.1

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

packages/blog/src/infrastructure/repositories/articles.repository.mock.ts

@@ -0,0 +1,54 @@
+import "reflect-metadata";
+import { injectable } from "inversify";
+
+import type { IArticlesRepository } from "../../application/repositories/articles.repository.interface";
+import type { Article } from "../../entities/models/article";
+
+@injectable()
+export class MockArticlesRepository implements IArticlesRepository {
+  private _articles: Article[] = [];
+
+  async getArticle(id: string): Promise<Article | undefined> {
+    return this._articles.find((a) => a.id === id);
+  }
+
+  async getArticleBySlug(slug: string): Promise<Article | undefined> {
+    return this._articles.find((a) => a.slug === slug);
+  }
+
+  async getArticles(options?: {
+    status?: string;
+    authorId?: string;
+    limit?: number;
+    offset?: number;
+  }): Promise<Article[]> {
+    let result = [...this._articles];
+    if (options?.status) {
+      result = result.filter((a) => a.status === options.status);
+    }
+    if (options?.authorId) {
+      result = result.filter((a) => a.authorId === options.authorId);
+    }
+    const offset = options?.offset ?? 0;
+    const limit = options?.limit ?? 50;
+    return result.slice(offset, offset + limit);
+  }
+
+  async createArticle(input: Article): Promise<Article> {
+    this._articles.push(input);
+    return input;
+  }
+
+  async updateArticle(
+    id: string,
+    input: Partial<Article>,
+  ): Promise<Article | undefined> {
+    const index = this._articles.findIndex((a) => a.id === id);
+    if (index === -1) return undefined;
+    const current = this._articles[index];
+    if (!current) return undefined;
+    const updated: Article = { ...current, ...input, id: current.id };
+    this._articles[index] = updated;
+    return updated;
+  }
+}