feat(features): add bind-dev-seed binders for auth/marketing-pages/navigation/media

Mirrors the canonical blog pattern landed earlier on this branch.

Per feature:
- src/__seeds__/dev.ts — lazy buildDev<Entities>() function using the
  feature's existing factory for sensible defaults
- src/di/bind-dev-seed.ts — bindDevSeed<Feature>() async function that
  rebinds the repo symbol(s) to a populated MockXRepository via
  .toConstantValue
- src/di/bind-dev-seed.test.ts — 3+ tests per feature (populates,
  reachable by id/slug, idempotent)
- package.json — adds ./di/bind-dev-seed subpath export

Tests + use cases continue to construct mocks directly; the seed never
runs from a *.test.ts path. App boot wiring (USE_DEV_SEED env branch)
follows in a separate commit.

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

packages/marketing-pages/src/di/bind-dev-seed.test.ts

@@ -0,0 +1,98 @@
+import "reflect-metadata";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { bindDevSeedMarketingPages } from "@/di/bind-dev-seed";
+import { marketingPagesContainer } from "@/di/container";
+import { MARKETING_PAGES_SYMBOLS } from "@/di/symbols";
+import { MockPagesRepository } from "@/infrastructure/repositories/pages.repository.mock";
+import { MockSiteSettingsRepository } from "@/infrastructure/repositories/site-settings.repository.mock";
+import type { IPagesRepository } from "@/application/repositories/pages.repository.interface";
+import type { ISiteSettingsRepository } from "@/application/repositories/site-settings.repository.interface";
+
+describe("bindDevSeedMarketingPages", () => {
+  // Each test starts from default mock bindings and tears down afterwards so
+  // the global marketingPagesContainer state stays clean for siblings.
+  beforeEach(() => {
+    if (marketingPagesContainer.isBound(MARKETING_PAGES_SYMBOLS.IPagesRepository)) {
+      marketingPagesContainer.unbind(MARKETING_PAGES_SYMBOLS.IPagesRepository);
+    }
+    marketingPagesContainer
+      .bind<IPagesRepository>(MARKETING_PAGES_SYMBOLS.IPagesRepository)
+      .to(MockPagesRepository);
+
+    if (
+      marketingPagesContainer.isBound(
+        MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository,
+      )
+    ) {
+      marketingPagesContainer.unbind(
+        MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository,
+      );
+    }
+    marketingPagesContainer
+      .bind<ISiteSettingsRepository>(MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository)
+      .to(MockSiteSettingsRepository);
+  });
+
+  afterEach(() => {
+    if (marketingPagesContainer.isBound(MARKETING_PAGES_SYMBOLS.IPagesRepository)) {
+      marketingPagesContainer.unbind(MARKETING_PAGES_SYMBOLS.IPagesRepository);
+    }
+    marketingPagesContainer
+      .bind<IPagesRepository>(MARKETING_PAGES_SYMBOLS.IPagesRepository)
+      .to(MockPagesRepository);
+
+    if (
+      marketingPagesContainer.isBound(
+        MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository,
+      )
+    ) {
+      marketingPagesContainer.unbind(
+        MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository,
+      );
+    }
+    marketingPagesContainer
+      .bind<ISiteSettingsRepository>(MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository)
+      .to(MockSiteSettingsRepository);
+  });
+
+  it("populates the pages repository with the dev pages", async () => {
+    await bindDevSeedMarketingPages();
+
+    const repo = marketingPagesContainer.get<IPagesRepository>(
+      MARKETING_PAGES_SYMBOLS.IPagesRepository,
+    );
+    const pages = await repo.getPages();
+
+    expect(pages.length).toBeGreaterThan(0);
+  });
+
+  it("seeds site settings with a non-default site name", async () => {
+    await bindDevSeedMarketingPages();
+
+    const settingsRepo = marketingPagesContainer.get<ISiteSettingsRepository>(
+      MARKETING_PAGES_SYMBOLS.ISiteSettingsRepository,
+    );
+    const settings = await settingsRepo.getSiteSettings();
+
+    expect(settings.siteName).toBe("My App");
+    expect(settings.siteDescription).toBeDefined();
+  });
+
+  it("is idempotent — calling twice rebuilds fresh populated repos", async () => {
+    await bindDevSeedMarketingPages();
+    const before = marketingPagesContainer.get<IPagesRepository>(
+      MARKETING_PAGES_SYMBOLS.IPagesRepository,
+    );
+    const beforeCount = (await before.getPages()).length;
+
+    await bindDevSeedMarketingPages();
+    const after = marketingPagesContainer.get<IPagesRepository>(
+      MARKETING_PAGES_SYMBOLS.IPagesRepository,
+    );
+    const afterCount = (await after.getPages()).length;
+
+    expect(afterCount).toBe(beforeCount);
+    // It's a fresh instance — not the previous one.
+    expect(after).not.toBe(before);
+  });
+});