feat(usage): add subscription quota windows per provider on /usage page

reads local claude and codex auth files server-side, calls provider
quota apis (anthropic oauth usage, chatgpt wham/usage), and surfaces
live usedPercent per window in ProviderQuotaCard with threshold fill colors

packages/shared/src/index.ts

@@ -189,6 +189,8 @@ export type {
   PluginJobRecord,
   PluginJobRunRecord,
   PluginWebhookDeliveryRecord,
+  QuotaWindow,
+  ProviderQuotaResult,
 } from "./types/index.js";
 
 export {