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/schema.ts

@@ -313,4 +313,23 @@ export default defineSchema({
   })
     .index("by_user", ["userId"])
     .index("by_session", ["sessionId"]),
+
+  // ─── Contact messages ───────────────────────────────────────────────────
+  messages: defineTable({
+    fullName: v.string(),
+    email: v.string(),
+    topic: v.union(
+      v.literal("products"),
+      v.literal("orders"),
+      v.literal("support"),
+      v.literal("other"),
+    ),
+    message: v.string(),
+    createdAt: v.number(),
+    bookmarked: v.optional(v.boolean()),
+    updatedAt: v.optional(v.number()),
+  })
+    .index("by_created_at", ["createdAt"])
+    .index("by_topic", ["topic"])
+    .index("by_bookmarked", ["bookmarked"]),
 });