feat(storefront): update FAQ and legal documentation

- Added new FAQ sections for account security, ordering and checkout, returns, shipping, and contact information.
- Introduced legal documents including privacy policy, terms of service, data protection, and general terms and conditions.
- Updated package dependencies to include gray-matter and remark-gfm for enhanced markdown support.

convex/messages.test.ts

@@ -0,0 +1,57 @@
+import { convexTest } from "convex-test";
+import { describe, it, expect } from "vitest";
+import { api } from "./_generated/api";
+import schema from "./schema";
+
+const modules = import.meta.glob("./**/*.ts");
+
+describe("messages.submit", () => {
+  it("creates one document with correct fields for valid payload", async () => {
+    const t = convexTest(schema, modules);
+    const messageId = await t.mutation(api.messages.submit, {
+      fullName: "Jane Doe",
+      email: "jane@example.com",
+      topic: "support",
+      message: "I need help with my order.",
+    });
+    expect(messageId).toBeTruthy();
+
+    await t.run(async (ctx) => {
+      const doc = await ctx.db.get(messageId);
+      expect(doc).not.toBeNull();
+      expect(doc!.fullName).toBe("Jane Doe");
+      expect(doc!.email).toBe("jane@example.com");
+      expect(doc!.topic).toBe("support");
+      expect(doc!.message).toBe("I need help with my order.");
+      expect(doc!.createdAt).toBeGreaterThan(0);
+      expect(doc!.bookmarked).toBe(false);
+    });
+  });
+
+  it("rejects invalid topic", async () => {
+    const t = convexTest(schema, modules);
+    await expect(
+      t.mutation(api.messages.submit, {
+        fullName: "Jane Doe",
+        email: "jane@example.com",
+        topic: "invalid_topic",
+        message: "Hello",
+      }),
+    ).rejects.toThrow();
+  });
+
+  it("rejects missing required fields", async () => {
+    const t = convexTest(schema, modules);
+    const invalidArgs = {
+      fullName: "Jane Doe",
+    };
+    await expect(
+      t.mutation(api.messages.submit, invalidArgs as {
+        fullName: string;
+        email: string;
+        topic: "products" | "orders" | "support" | "other";
+        message: string;
+      }),
+    ).rejects.toThrow();
+  });
+});