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/site-settings.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  DEFAULT_SITE_PRIMARY_COLOR,
+  buildDefaultSiteSettings,
+  normalizeSiteDefaultLocale,
+  normalizeSitePrimaryColor,
+  parseSiteSettingsValue,
+} from "@/lib/site-settings";
+
+describe("normalizeSiteDefaultLocale", () => {
+  it("keeps the three supported locales", () => {
+    expect(normalizeSiteDefaultLocale("ar")).toBe("ar");
+    expect(normalizeSiteDefaultLocale("en")).toBe("en");
+    expect(normalizeSiteDefaultLocale("de")).toBe("de");
+  });
+
+  it("defaults to de for anything else", () => {
+    expect(normalizeSiteDefaultLocale("fr")).toBe("de");
+    expect(normalizeSiteDefaultLocale(undefined)).toBe("de");
+    expect(normalizeSiteDefaultLocale(123)).toBe("de");
+  });
+});
+
+describe("normalizeSitePrimaryColor", () => {
+  it("accepts and lowercases 6-digit hex", () => {
+    expect(normalizeSitePrimaryColor("#AABBCC")).toBe("#aabbcc");
+    expect(normalizeSitePrimaryColor("  #112233 ")).toBe("#112233");
+  });
+
+  it("rejects invalid colors", () => {
+    expect(normalizeSitePrimaryColor("red")).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+    expect(normalizeSitePrimaryColor("#abc")).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+    expect(normalizeSitePrimaryColor("#12345g")).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+    expect(normalizeSitePrimaryColor(42)).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+    expect(normalizeSitePrimaryColor(null)).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+  });
+});
+
+describe("buildDefaultSiteSettings", () => {
+  it("uses the fallback name across all locales", () => {
+    const settings = buildDefaultSiteSettings("Studio Moh");
+    expect(settings.defaultLocale).toBe("de");
+    expect(settings.brand.primaryColor).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+    expect(settings.locales.ar.siteName).toBe("Studio Moh");
+    expect(settings.locales.en.titleTemplate).toBe("{pageTitle} | {siteName}");
+    expect(settings.locales.de.subhead).toBe("");
+  });
+});
+
+describe("parseSiteSettingsValue", () => {
+  it("returns defaults for empty input", () => {
+    expect(parseSiteSettingsValue(null, "Fallback")).toEqual(buildDefaultSiteSettings("Fallback"));
+  });
+
+  it("returns defaults for invalid json", () => {
+    expect(parseSiteSettingsValue("{bad", "Fallback")).toEqual(buildDefaultSiteSettings("Fallback"));
+  });
+
+  it("merges stored values with safe defaults", () => {
+    const settings = parseSiteSettingsValue(
+      JSON.stringify({
+        defaultLocale: "ar",
+        brand: { primaryColor: "#112233" },
+        locales: {
+          en: { siteName: "Brand EN", titleTemplate: "{pageTitle} - {siteName}", siteDescription: "English" },
+          de: { siteName: "Brand DE", subhead: "Sub" },
+        },
+      }),
+      "Fallback",
+    );
+    expect(settings.defaultLocale).toBe("ar");
+    expect(settings.brand.primaryColor).toBe("#112233");
+    expect(settings.locales.en.siteName).toBe("Brand EN");
+    expect(settings.locales.en.titleTemplate).toBe("{pageTitle} - {siteName}");
+    expect(settings.locales.en.subhead).toBe("");
+    expect(settings.locales.ar.siteName).toBe("Fallback");
+    expect(settings.locales.de.subhead).toBe("Sub");
+  });
+
+  it("ignores title templates that lack the {pageTitle} token", () => {
+    const settings = parseSiteSettingsValue(
+      JSON.stringify({ locales: { en: { siteName: "X", titleTemplate: "no token here" } } }),
+      "Fallback",
+    );
+    expect(settings.locales.en.titleTemplate).toBe("{pageTitle} | {siteName}");
+  });
+
+  it("falls back for invalid default locale and primary color", () => {
+    const settings = parseSiteSettingsValue(
+      JSON.stringify({ defaultLocale: "fr", brand: { primaryColor: "nope" } }),
+      "Fallback",
+    );
+    expect(settings.defaultLocale).toBe("de");
+    expect(settings.brand.primaryColor).toBe(DEFAULT_SITE_PRIMARY_COLOR);
+  });
+
+  it("trims string fields", () => {
+    const settings = parseSiteSettingsValue(
+      JSON.stringify({ locales: { de: { siteName: "  Trimmed  ", siteDescription: "  d  " } } }),
+      "Fallback",
+    );
+    expect(settings.locales.de.siteName).toBe("Trimmed");
+    expect(settings.locales.de.siteDescription).toBe("d");
+  });
+});