fix: prevent false positive context overflow detection in conversation text (#2078)

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

@@ -24,7 +24,7 @@ export function isContextOverflowError(errorMessage?: string): boolean {
     lower.includes("prompt is too long") ||
     lower.includes("exceeds model context window") ||
     (hasRequestSizeExceeds && hasContextWindow) ||
-    lower.includes("context overflow") ||
+    lower.includes("context overflow:") ||
     (lower.includes("413") && lower.includes("too large"))
   );
 }