feat: add Team billing tier

Widens the tier enum from free/pro to free/pro/team and every
"free" | "pro" cast that assumed exactly two tiers (~30 call sites:
every AI route's withAiQuota/checkAndIncrementTierLimit call, admin
user/invite management, upload quota checks, OpenAPI schemas). Team
sits above Pro with genuinely unlimited recipes/public-recipes (the
-1 sentinel, which Pro doesn't actually use — Pro uses large finite
numbers instead) and a higher AI-call/storage cap. Seeded via
db:seed, editable afterward from Admin > Tiers.

role (user/moderator/admin — permissions) and tier (free/pro/team —
billing limits) stay separate concepts, as they already were; this
does not touch role-based permissions.

Requires migration 0043 to run against a live DB — not applied in
this sandbox (no Docker here); run `pnpm db:migrate` then `pnpm db:seed`.

v0.44.0

apps/web/app/api/v1/admin/tiers/[tier]/route.ts

@@ -16,7 +16,7 @@ export async function PATCH(req: NextRequest, { params }: RouteContext) {
   if (response) return response;
 
   const { tier } = await params;
-  if (tier !== "free" && tier !== "pro") {
+  if (tier !== "free" && tier !== "pro" && tier !== "team") {
     return NextResponse.json({ error: "Invalid tier" }, { status: 400 });
   }