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,