fix(agents): cap embedded runner retry loop

src/agents/pi-embedded-runner/run.ts

@@ -102,6 +102,9 @@ function createCompactionDiagId(): string {
   return `ovf-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 8)}`;
 }
 
+// Defensive guard for the outer run loop across all retry branches.
+const MAX_RUN_RETRY_ITERATIONS = 24;
+
 const hasUsageValues = (
   usage: ReturnType<typeof normalizeUsage>,
 ): usage is NonNullable<ReturnType<typeof normalizeUsage>> =>
@@ -475,13 +478,42 @@ export async function runEmbeddedPiAgent(
       }
 
       const MAX_OVERFLOW_COMPACTION_ATTEMPTS = 3;
+      const MAX_RUN_LOOP_ITERATIONS = MAX_RUN_RETRY_ITERATIONS;
       let overflowCompactionAttempts = 0;
       let toolResultTruncationAttempted = false;
       const usageAccumulator = createUsageAccumulator();
       let lastRunPromptUsage: ReturnType<typeof normalizeUsage> | undefined;
       let autoCompactionCount = 0;
+      let runLoopIterations = 0;
       try {
         while (true) {
+          if (runLoopIterations >= MAX_RUN_LOOP_ITERATIONS) {
+            const message = `Exceeded retry limit after ${runLoopIterations} attempts.`;
+            log.error(
+              `[run-retry-limit] sessionKey=${params.sessionKey ?? params.sessionId} ` +
+                `provider=${provider}/${modelId} attempts=${runLoopIterations}`,
+            );
+            return {
+              payloads: [
+                {
+                  text:
+                    "Request failed after repeated internal retries. " +
+                    "Please try again, or use /new to start a fresh session.",
+                  isError: true,
+                },
+              ],
+              meta: {
+                durationMs: Date.now() - started,
+                agentMeta: {
+                  sessionId: params.sessionId,
+                  provider,
+                  model: model.id,
+                },
+                error: { kind: "retry_limit", message },
+              },
+            };
+          }
+          runLoopIterations += 1;
           attemptedThinking.add(thinkLevel);
           await fs.mkdir(resolvedWorkspace, { recursive: true });