feat: initial commit — storefront, convex backend, and shared packages

Completes the first milestone of The Pet Loft ecommerce platform:
- apps/storefront: full customer-facing Next.js app with HeroUI (cart,
  checkout, orders, wishlist, product detail, shop, search, auth)
- convex/: serverless backend with schema, queries, mutations, actions,
  HTTP routes, Stripe/Shippo integrations, and co-located tests
- packages/types, packages/utils, packages/convex: shared workspace packages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

convex/model/products.ts

@@ -0,0 +1,80 @@
+import { QueryCtx, MutationCtx } from "../_generated/server";
+import { Id } from "../_generated/dataModel";
+
+/**
+ * Recalculate product averageRating and reviewCount from approved reviews.
+ * Call after review approve/delete.
+ */
+export async function recalculateProductRating(
+  ctx: MutationCtx,
+  productId: Id<"products">,
+) {
+  const approved = await ctx.db
+    .query("reviews")
+    .withIndex("by_product_approved", (q) =>
+      q.eq("productId", productId).eq("isApproved", true),
+    )
+    .collect();
+
+  const count = approved.length;
+  const averageRating =
+    count > 0
+      ? approved.reduce((sum, r) => sum + r.rating, 0) / count
+      : undefined;
+  const reviewCount = count > 0 ? count : undefined;
+
+  await ctx.db.patch(productId, {
+    averageRating,
+    reviewCount,
+    updatedAt: Date.now(),
+  });
+}
+
+export async function getProductWithRelations(
+  ctx: QueryCtx,
+  productId: Id<"products">,
+) {
+  const product = await ctx.db.get(productId);
+  if (!product) return null;
+
+  const [imagesRaw, variants, category] = await Promise.all([
+    ctx.db
+      .query("productImages")
+      .withIndex("by_product", (q) => q.eq("productId", productId))
+      .collect(),
+    ctx.db
+      .query("productVariants")
+      .withIndex("by_product_and_active", (q) =>
+        q.eq("productId", productId).eq("isActive", true),
+      )
+      .collect(),
+    ctx.db.get(product.categoryId),
+  ]);
+  const images = imagesRaw.sort((a, b) => a.position - b.position);
+
+  return { ...product, images, variants, category };
+}
+
+export async function enrichProducts(
+  ctx: QueryCtx,
+  products: Awaited<ReturnType<typeof ctx.db.query>>[],
+) {
+  return Promise.all(
+    products.map(async (product: any) => {
+      const [imagesRaw, variants] = await Promise.all([
+        ctx.db
+          .query("productImages")
+          .withIndex("by_product", (q) => q.eq("productId", product._id))
+          .collect(),
+        ctx.db
+          .query("productVariants")
+          .withIndex("by_product_and_active", (q) =>
+            q.eq("productId", product._id).eq("isActive", true),
+          )
+          .collect(),
+      ]);
+      const images = imagesRaw.sort((a, b) => a.position - b.position);
+      return { ...product, images, variants };
+    }),
+  );
+}