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

packages/db/src/schema/users.ts

@@ -10,7 +10,7 @@ import {
 import { relations } from "drizzle-orm";
 
 export const userRoleEnum = pgEnum("user_role", ["user", "moderator", "admin"]);
-export const tierEnum = pgEnum("tier", ["free", "pro"]);
+export const tierEnum = pgEnum("tier", ["free", "pro", "team"]);
 export const unitPrefEnum = pgEnum("unit_pref", ["metric", "imperial"]);
 export const apiKeyScopeEnum = pgEnum("api_key_scope", ["full", "read"]);