Fix Cloud Code Assist API errors (429/400)

- Enhanced rate limit detection for Cloud Code Assist quota exhaustion
- Added tool call ID sanitization to fix invalid request format errors
- Integrated Cloud Code Assist format error detection into failover system
- Added comprehensive error pattern matching for Cloud Code Assist APIs

Fixes #cloud-code-assist-api-errors

src/agents/pi-embedded-runner.ts

@@ -61,6 +61,7 @@ import {
   ensureSessionHeader,
   formatAssistantErrorText,
   isAuthAssistantError,
+  isCloudCodeAssistFormatError,
   isContextOverflowError,
   isFailoverAssistantError,
   isFailoverErrorMessage,
@@ -1523,9 +1524,15 @@ export async function runEmbeddedPiAgent(params: {
           const assistantFailoverReason = classifyFailoverReason(
             lastAssistant?.errorMessage ?? "",
           );
+          const cloudCodeAssistFormatError = lastAssistant?.errorMessage
+            ? isCloudCodeAssistFormatError(lastAssistant.errorMessage)
+            : false;
 
           // Treat timeout as potential rate limit (Antigravity hangs on rate limit)
-          const shouldRotate = (!aborted && failoverFailure) || timedOut;
+          const shouldRotate =
+            (!aborted &&
+              (failoverFailure || cloudCodeAssistFormatError)) ||
+            timedOut;
 
           if (shouldRotate) {
             // Mark current profile for cooldown before rotating
@@ -1546,6 +1553,11 @@ export async function runEmbeddedPiAgent(params: {
                   `Profile ${lastProfileId} timed out (possible rate limit). Trying next account...`,
                 );
               }
+              if (cloudCodeAssistFormatError) {
+                log.warn(
+                  `Profile ${lastProfileId} hit Cloud Code Assist format error. Tool calls will be sanitized on retry.`,
+                );
+              }
             }
             const rotated = await advanceAuthProfile();
             if (rotated) {