refactor(quota): move provider quota logic into adapter layer, add unit tests

- Extract all Anthropic credential/API logic into claude-local/src/server/quota.ts
- Extract all OpenAI/WHAM credential/API logic into codex-local/src/server/quota.ts
- Add optional getQuotaWindows() to ServerAdapterModule in adapter-utils
- Rewrite quota-windows.ts as a 29-line thin aggregator with zero provider knowledge
- Wire getQuotaWindows into adapter registry for claude-local and codex-local
- Add 47 unit tests covering toPercent, secondsToWindowLabel, WHAM normalization,
  readClaudeToken, readCodexToken, fetchClaudeQuota, fetchCodexQuota, fetchWithTimeout
- Add 8 unit tests covering parseDateRange validation and byProvider pro-rata math

Adding a third provider now requires only touching that provider's adapter.

packages/adapter-utils/src/index.ts

@@ -17,6 +17,8 @@ export type {
   HireApprovedPayload,
   HireApprovedHookResult,
   ServerAdapterModule,
+  QuotaWindow,
+  ProviderQuotaResult,
   TranscriptEntry,
   StdoutLineParser,
   CLIAdapterModule,

packages/adapter-utils/src/types.ts

@@ -171,6 +171,33 @@ export interface HireApprovedHookResult {
   detail?: Record<string, unknown>;
 }
 
+// ---------------------------------------------------------------------------
+// Quota window types — used by adapters that can report provider quota/rate-limit state
+// ---------------------------------------------------------------------------
+
+/** a single rate-limit or usage window returned by a provider quota API */
+export interface QuotaWindow {
+  /** human label, e.g. "5h", "7d", "Sonnet 7d", "Credits" */
+  label: string;
+  /** percent of the window already consumed (0-100), null when not reported */
+  usedPercent: number | null;
+  /** iso timestamp when this window resets, null when not reported */
+  resetsAt: string | null;
+  /** free-form value label for credit-style windows, e.g. "$4.20 remaining" */
+  valueLabel: string | null;
+}
+
+/** result for one provider from getQuotaWindows() */
+export interface ProviderQuotaResult {
+  /** provider slug, e.g. "anthropic", "openai" */
+  provider: string;
+  /** true when the fetch succeeded and windows is populated */
+  ok: boolean;
+  /** error message when ok is false */
+  error?: string;
+  windows: QuotaWindow[];
+}
+
 export interface ServerAdapterModule {
   type: string;
   execute(ctx: AdapterExecutionContext): Promise<AdapterExecutionResult>;
@@ -188,6 +215,12 @@ export interface ServerAdapterModule {
     payload: HireApprovedPayload,
     adapterConfig: Record<string, unknown>,
   ) => Promise<HireApprovedHookResult>;
+  /**
+   * Optional: fetch live provider quota/rate-limit windows for this adapter.
+   * Returns a ProviderQuotaResult so the server can aggregate across adapters
+   * without knowing provider-specific credential paths or API shapes.
+   */
+  getQuotaWindows?: () => Promise<ProviderQuotaResult>;
 }
 
 // ---------------------------------------------------------------------------