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/unit/media-service.test.ts

@@ -0,0 +1,52 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  getKindFromUploadFile,
+  inferMediaKindFromFileName,
+  inferMediaKindFromMimeType,
+} from "@/lib/media-service";
+
+describe("inferMediaKindFromMimeType", () => {
+  it("classifies image mime types as IMAGE", () => {
+    expect(inferMediaKindFromMimeType("image/png")).toBe("IMAGE");
+    expect(inferMediaKindFromMimeType("image/svg+xml")).toBe("IMAGE");
+    expect(inferMediaKindFromMimeType("image/gif")).toBe("IMAGE");
+  });
+
+  it("classifies everything else as DOCUMENT", () => {
+    expect(inferMediaKindFromMimeType("application/pdf")).toBe("DOCUMENT");
+    expect(inferMediaKindFromMimeType(null)).toBe("DOCUMENT");
+    expect(inferMediaKindFromMimeType(undefined)).toBe("DOCUMENT");
+    expect(inferMediaKindFromMimeType("")).toBe("DOCUMENT");
+  });
+});
+
+describe("inferMediaKindFromFileName", () => {
+  it("treats known image extensions as IMAGE (case-insensitive)", () => {
+    for (const name of ["a.gif", "a.jpg", "a.jpeg", "a.PNG", "a.webp", "a.SVG"]) {
+      expect(inferMediaKindFromFileName(name)).toBe("IMAGE");
+    }
+  });
+
+  it("treats other extensions as DOCUMENT", () => {
+    expect(inferMediaKindFromFileName("report.pdf")).toBe("DOCUMENT");
+    expect(inferMediaKindFromFileName("noext")).toBe("DOCUMENT");
+  });
+});
+
+describe("getKindFromUploadFile", () => {
+  it("derives IMAGE from an image mime type", () => {
+    const file = new File([new Uint8Array([1])], "logo.png", { type: "image/png" });
+    expect(getKindFromUploadFile(file)).toBe("IMAGE");
+  });
+
+  it("derives DOCUMENT from a pdf mime type", () => {
+    const file = new File([new Uint8Array([1])], "doc.pdf", { type: "application/pdf" });
+    expect(getKindFromUploadFile(file)).toBe("DOCUMENT");
+  });
+
+  it("falls back to DOCUMENT for unknown mime types", () => {
+    const file = new File([new Uint8Array([1])], "thing.bin", { type: "application/octet-stream" });
+    expect(getKindFromUploadFile(file)).toBe("DOCUMENT");
+  });
+});