fix(agents): keep upgrade-plan 402s in billing

src/agents/failover-error.test.ts

@@ -241,6 +241,21 @@ describe("failover-error", () => {
     ).toBe("rate_limit");
   });
 
+  it("keeps plan-upgrade 402 wrappers aligned with status-split billing payloads", () => {
+    const message = "Your usage limit has been reached. Please upgrade your plan.";
+    expect(
+      resolveFailoverReasonFromError({
+        message: `HTTP 402 Payment Required: ${message}`,
+      }),
+    ).toBe("billing");
+    expect(
+      resolveFailoverReasonFromError({
+        status: 402,
+        message,
+      }),
+    ).toBe("billing");
+  });
+
   it("infers format errors from error messages", () => {
     expect(
       resolveFailoverReasonFromError({

src/agents/pi-embedded-helpers.isbillingerrormessage.test.ts

@@ -579,6 +579,12 @@ describe("classifyFailoverReasonFromHttpStatus – 402 temporary limits", () =>
     );
     expect(classifyFailoverReasonFromHttpStatus(402, transientMessage)).toBe("rate_limit");
   });
+
+  it("keeps plan-upgrade 402 limit messages in billing", () => {
+    const billingMessage = "Your usage limit has been reached. Please upgrade your plan.";
+    expect(classifyFailoverReason(`HTTP 402 Payment Required: ${billingMessage}`)).toBe("billing");
+    expect(classifyFailoverReasonFromHttpStatus(402, billingMessage)).toBe("billing");
+  });
 });
 
 describe("classifyFailoverReason", () => {

src/agents/pi-embedded-helpers/errors.ts

@@ -219,6 +219,12 @@ const BILLING_402_HINTS = [
   "add more credits",
   "top up",
 ] as const;
+const BILLING_402_PLAN_HINTS = [
+  "upgrade your plan",
+  "upgrade plan",
+  "current plan",
+  "subscription",
+] as const;
 
 const PERIODIC_402_HINTS = ["daily", "weekly", "monthly"] as const;
 const RETRYABLE_402_RETRY_HINTS = ["try again", "retry", "temporary", "cooldown"] as const;
@@ -242,6 +248,7 @@ function includesAnyHint(text: string, hints: readonly string[]): boolean {
 function hasExplicit402BillingSignal(text: string): boolean {
   return (
     includesAnyHint(text, BILLING_402_HINTS) ||
+    (includesAnyHint(text, BILLING_402_PLAN_HINTS) && text.includes("limit")) ||
     text.includes("billing hard limit") ||
     text.includes("hard limit reached") ||
     (text.includes("maximum allowed") && text.includes("limit"))