feat(quota): add Claude OAuth usage quota detection

Add Claude quota section to the Quota Management page, using the
Anthropic OAuth usage API (api.anthropic.com/api/oauth/usage) to
display utilization across all rate limit windows (5-hour, 7-day,
Opus, Sonnet, etc.) and extra usage credits.

src/types/quota.ts

@@ -97,6 +97,46 @@ export interface CodexUsagePayload {
   codeReviewRateLimit?: CodexRateLimitInfo | null;
 }
 
+// Claude API payload types
+export interface ClaudeUsageWindow {
+  utilization: number;
+  resets_at: string;
+}
+
+export interface ClaudeExtraUsage {
+  is_enabled: boolean;
+  monthly_limit: number;
+  used_credits: number;
+  utilization: number | null;
+}
+
+export interface ClaudeUsagePayload {
+  five_hour?: ClaudeUsageWindow | null;
+  seven_day?: ClaudeUsageWindow | null;
+  seven_day_oauth_apps?: ClaudeUsageWindow | null;
+  seven_day_opus?: ClaudeUsageWindow | null;
+  seven_day_sonnet?: ClaudeUsageWindow | null;
+  seven_day_cowork?: ClaudeUsageWindow | null;
+  iguana_necktie?: ClaudeUsageWindow | null;
+  extra_usage?: ClaudeExtraUsage | null;
+}
+
+export interface ClaudeQuotaWindow {
+  id: string;
+  label: string;
+  labelKey?: string;
+  usedPercent: number | null;
+  resetLabel: string;
+}
+
+export interface ClaudeQuotaState {
+  status: 'idle' | 'loading' | 'success' | 'error';
+  windows: ClaudeQuotaWindow[];
+  extraUsage?: ClaudeExtraUsage | null;
+  error?: string;
+  errorStatus?: number;
+}
+
 // Quota state types
 export interface AntigravityQuotaGroup {
   id: string;