feat(web): show Codex plan usage in header

src/usage-telemetry.ts

@@ -1,5 +1,5 @@
 /**
- * @fileoverview Pure parsing + formatting of Claude Code statusline telemetry.
+ * @fileoverview Pure parsing + formatting of Claude and Codex plan telemetry.
  *
  * Claude Code (v2.1.80+) pipes a JSON blob to a configured `statusLine.command`
  * on each render. On Pro/Max subscriptions that blob carries a `rate_limits`
@@ -15,7 +15,10 @@
  * Only those two windows exist (no Opus-weekly field). `rate_limits` is absent
  * before the first API response and for non-subscriber auth — both yield null.
  *
- * All functions are pure for testability. See `test/usage-telemetry.test.ts`.
+ * The Codex parser consumes the read-only `account/rateLimits/read` app-server
+ * response and selects only the main `codex` bucket, excluding model-specific
+ * buckets. All functions are pure for testability. See
+ * `test/usage-telemetry.test.ts` and `test/codex-plan-usage.test.ts`.
  *
  * @module usage-telemetry
  */
@@ -51,6 +54,22 @@ export interface RawStatuslinePayload {
   model?: { display_name?: string };
 }
 
+interface RawCodexRateLimitWindow {
+  usedPercent?: unknown;
+  windowDurationMins?: unknown;
+  resetsAt?: unknown;
+}
+
+interface RawCodexRateLimitSnapshot {
+  primary?: RawCodexRateLimitWindow | null;
+  secondary?: RawCodexRateLimitWindow | null;
+}
+
+interface RawCodexRateLimitsResponse {
+  rateLimits?: RawCodexRateLimitSnapshot | null;
+  rateLimitsByLimitId?: Record<string, RawCodexRateLimitSnapshot | null> | null;
+}
+
 function clampPct(n: number): number {
   if (!Number.isFinite(n)) return 0;
   return Math.max(0, Math.min(100, n));
@@ -88,6 +107,29 @@ export function parseStatusTelemetry(data: RawStatuslinePayload | undefined): St
   return t;
 }
 
+/** Normalize the main Codex app-server bucket into the chip's two known windows. */
+export function parseCodexRateLimitsResponse(value: unknown): StatusTelemetry | null {
+  if (!value || typeof value !== 'object') return null;
+  const response = value as RawCodexRateLimitsResponse;
+  const snapshot = response.rateLimitsByLimitId?.codex ?? response.rateLimits;
+  if (!snapshot || typeof snapshot !== 'object') return null;
+
+  const telemetry: StatusTelemetry = {};
+  for (const window of [snapshot.primary, snapshot.secondary]) {
+    if (!window || typeof window.usedPercent !== 'number' || !Number.isFinite(window.usedPercent)) continue;
+    if (window.windowDurationMins !== 300 && window.windowDurationMins !== 10_080) continue;
+    const resetsAt =
+      typeof window.resetsAt === 'number' && Number.isFinite(window.resetsAt) && window.resetsAt > 0
+        ? Math.round(window.resetsAt * 1000)
+        : 0;
+    const normalized = { usedPercentage: clampPct(window.usedPercent), resetAt: resetsAt };
+    if (window.windowDurationMins === 300) telemetry.fiveHour = normalized;
+    if (window.windowDurationMins === 10_080) telemetry.sevenDay = normalized;
+  }
+
+  return telemetry.fiveHour || telemetry.sevenDay ? telemetry : null;
+}
+
 /**
  * Current-session status for the in-terminal statusline footer. This is the
  * "status of the current session" the user sees in Claude's footer — distinct