[WRONG BRANCH] fix(gui+server): reject out-of-range quota expiry timestamps

gui/src/provider-workspace/report.ts

@@ -39,6 +39,13 @@ const finite = (value: unknown): number | undefined => (
   typeof value === "number" && Number.isFinite(value) ? value : undefined
 );
 
+const dateTimestamp = (value: unknown): number | undefined => {
+  const timestamp = finite(value);
+  if (timestamp === undefined) return undefined;
+  const milliseconds = timestamp > 10_000_000_000 ? timestamp : timestamp * 1000;
+  return Number.isFinite(new Date(milliseconds).getTime()) ? timestamp : undefined;
+};
+
 function quotaFromUnknown(quota: unknown, fallbackUpdatedAt?: number): AccountQuota | null {
   if (!quota || typeof quota !== "object" || Array.isArray(quota)) return null;
   const q = quota as Record<string, unknown>;
@@ -61,7 +68,7 @@ function quotaFromUnknown(quota: unknown, fallbackUpdatedAt?: number): AccountQu
   const creditsLimit = finite(creditsRaw?.limit);
   const creditsRemaining = finite(creditsRaw?.remaining);
   const creditsPercent = finite(creditsRaw?.percent);
-  const creditsExpiresAt = finite(creditsRaw?.expiresAt);
+  const creditsExpiresAt = dateTimestamp(creditsRaw?.expiresAt);
   const creditsUsd = creditsUsed !== undefined
     && creditsLimit !== undefined
     && creditsRemaining !== undefined

gui/tests/provider-capacity-credits.test.tsx

@@ -39,3 +39,9 @@ test("credits with an expiry render the localized billing-period end date", () =
   expect(markup).toContain("Credits balance");
   expect(markup).toContain("Billing period ends 26 Aug 2026");
 });
+
+test("credits with an out-of-range expiry render without the billing-period line", () => {
+  const markup = renderCredits(1e20);
+  expect(markup).toContain("Credits balance");
+  expect(markup).not.toContain("Billing period ends");
+});

gui/tests/provider-capacity.test.ts

@@ -61,6 +61,22 @@ test("provider quota reports reject malformed required credits and drop malforme
     creditsUsd: { used: 12.5, limit: 50, remaining: 37.5, percent: 25 },
     updatedAt: 123,
   });
+
+  expect(accountQuotaFromReport({
+    updatedAt: 123,
+    quota: {
+      creditsUsd: {
+        used: 12.5,
+        limit: 50,
+        remaining: 37.5,
+        percent: 25,
+        expiresAt: 1e20,
+      },
+    },
+  })).toEqual({
+    creditsUsd: { used: 12.5, limit: 50, remaining: 37.5, percent: 25 },
+    updatedAt: 123,
+  });
 });
 
 test("capacity metadata preserves estimate, raw current quota, recovery percent, and incomplete coverage", () => {

src/providers/quota.ts

@@ -279,7 +279,8 @@ function normalizeResetAt(value: unknown): number | undefined {
 /** Unix 0 / negative values are sentinels, not reset clocks (Command Code fiveHour.resetAt: 0). */
 function epochMillis(value: number): number | undefined {
   if (!Number.isFinite(value) || value <= 0) return undefined;
-  return value > 10_000_000_000 ? value : value * 1000;
+  const milliseconds = value > 10_000_000_000 ? value : value * 1000;
+  return Number.isFinite(new Date(milliseconds).getTime()) ? milliseconds : undefined;
 }
 
 function toFiniteNumber(value: unknown): number | undefined {

tests/command-code-quota.test.ts

@@ -333,13 +333,13 @@ describe("Command Code provider quota", () => {
     expect(result.reports).toEqual([]);
   });
 
-  test("a fully exhausted account still reports a zero-remaining credit window", async () => {
+  test("a fully exhausted account drops an out-of-range subscription expiry", async () => {
     globalThis.fetch = (async (input: RequestInfo | URL) => {
       const url = String(input);
       const body = url.includes("/alpha/whoami")
         ? {}
         : url.includes("/alpha/billing/subscriptions")
-          ? { data: { currentPeriodStart: "2026-08-01T00:00:00.000Z", currentPeriodEnd: "2026-09-01T00:00:00.000Z" } }
+          ? { data: { currentPeriodStart: "2026-08-01T00:00:00.000Z", currentPeriodEnd: 1e20 } }
           : url.includes("/alpha/usage/summary")
             ? { totalCost: 12 }
             : {
@@ -358,7 +358,6 @@ describe("Command Code provider quota", () => {
         limit: 12,
         remaining: 0,
         percent: 100,
-        expiresAt: Date.parse("2026-09-01T00:00:00.000Z"),
       },
       updatedAt: expect.any(Number),
     });