fix: reset session after compaction overflow

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

@@ -7,6 +7,7 @@ import {
   formatAssistantErrorText,
   isBillingErrorMessage,
   isCloudCodeAssistFormatError,
+  isCompactionFailureError,
   isContextOverflowError,
   isFailoverErrorMessage,
   isMessagingToolDuplicate,
@@ -208,6 +209,8 @@ describe("isContextOverflowError", () => {
       "Request exceeds the maximum size",
       "context length exceeded",
       "Maximum context length",
+      "prompt is too long: 208423 tokens > 200000 maximum",
+      "Context overflow: Summarization failed",
       "413 Request Entity Too Large",
     ];
     for (const sample of samples) {
@@ -220,6 +223,26 @@ describe("isContextOverflowError", () => {
   });
 });
 
+describe("isCompactionFailureError", () => {
+  it("matches compaction overflow failures", () => {
+    const samples = [
+      "Context overflow: Summarization failed: 400 {\"message\":\"prompt is too long\"}",
+      "auto-compaction failed due to context overflow",
+      "Compaction failed: prompt is too long",
+    ];
+    for (const sample of samples) {
+      expect(isCompactionFailureError(sample)).toBe(true);
+    }
+  });
+
+  it("ignores non-compaction overflow errors", () => {
+    expect(
+      isCompactionFailureError("Context overflow: prompt too large"),
+    ).toBe(false);
+    expect(isCompactionFailureError("rate limit exceeded")).toBe(false);
+  });
+});
+
 describe("isBillingErrorMessage", () => {
   it("matches credit / payment failures", () => {
     const samples = [