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

ui/src/lib/queryKeys.ts

@@ -75,6 +75,8 @@ export const queryKeys = {
     ["usage-by-provider", companyId, from, to] as const,
   usageWindowSpend: (companyId: string) =>
     ["usage-window-spend", companyId] as const,
+  usageQuotaWindows: (companyId: string) =>
+    ["usage-quota-windows", companyId] as const,
   heartbeats: (companyId: string, agentId?: string) =>
     ["heartbeats", companyId, agentId] as const,
   runDetail: (runId: string) => ["heartbeat-run", runId] as const,