test: add comprehensive automated test coverage

- Vitest multi-project setup (unit / integration / component)
- Real-Postgres integration harness via in-process PGlite (TEST_DATABASE_URL
  override), migrations applied per worker; production code untouched
- Unit: routing, locale, validation/Zod schemas, metadata, mail, site-theme,
  marquee, media, portfolio helpers, plus architecture-rule tests
- Integration: Prisma data layer, API routes, and all server actions
- Component: UI primitives and form components (jsdom + Testing Library)
- 371 tests passing

tests/integration/_smoke.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest";
+
+import { prisma } from "@/lib/prisma";
+
+describe("integration harness smoke test", () => {
+  it("connects to the migrated test database and performs CRUD", async () => {
+    const created = await prisma.category.create({
+      data: {
+        slug: "smoke",
+        nameAr: "a",
+        nameEn: "b",
+        nameDe: "c",
+        descriptionAr: "a",
+        descriptionEn: "b",
+        descriptionDe: "c",
+      },
+    });
+
+    expect(created.id).toBeTruthy();
+    expect(created.isActive).toBe(true);
+
+    const found = await prisma.category.findUnique({ where: { slug: "smoke" } });
+    expect(found?.nameEn).toBe("b");
+  });
+
+  it("resets the database between tests", async () => {
+    const count = await prisma.category.count();
+    expect(count).toBe(0);
+  });
+
+  it("supports enums and appconfig upsert", async () => {
+    await prisma.appConfig.upsert({
+      where: { key: "k" },
+      update: { value: "v2" },
+      create: { key: "k", value: "v1" },
+    });
+    const row = await prisma.appConfig.findUnique({ where: { key: "k" } });
+    expect(row?.value).toBe("v1");
+  });
+});