fix: drop .js extensions from remaining relative imports

Extends 8111639 to cover __factories__, __seeds__, __contracts__, and
core-testing barrels.

packages/blog/src/__contracts__/articles-repository.contract.ts

@@ -1,7 +1,7 @@
 import { it, expect, beforeEach, describe } from "vitest";
 import { defineContractSuite } from "@repo/core-testing/contract";
-import type { IArticlesRepository } from "../application/repositories/articles.repository.interface.js";
-import { articleFactory } from "../__factories__/article.factory.js";
+import type { IArticlesRepository } from "../application/repositories/articles.repository.interface";
+import { articleFactory } from "../__factories__/article.factory";
 
 export const articlesRepositoryContract =
   defineContractSuite<IArticlesRepository>(

packages/blog/src/__factories__/article.factory.ts

@@ -1,5 +1,5 @@
 import { defineFactory } from "@repo/core-testing/factory";
-import type { Article } from "../entities/models/article.js";
+import type { Article } from "../entities/models/article";
 
 export const articleFactory = defineFactory<Article>(({ sequence }) => ({
   id: `article-${sequence}`,

packages/blog/src/__factories__/index.ts

@@ -1 +1 @@
-export { articleFactory } from "./article.factory.js";
+export { articleFactory } from "./article.factory";

packages/blog/src/__seeds__/dev.ts

@@ -1,5 +1,5 @@
-import { articleFactory } from "../__factories__/article.factory.js";
-import type { Article } from "../entities/models/article.js";
+import { articleFactory } from "../__factories__/article.factory";
+import type { Article } from "../entities/models/article";
 
 /**
  * Realistic blog seed for dev mode + storybook stories.