feat(S-104): Add stderr-length and exit-code correlation diagnostics

tools/ai-cli-dispatch/src/execute.ts

@@ -90,15 +90,17 @@ export async function executePrompt(
       clearTimeout(timeout);
       const durationMs = Date.now() - startMs;
       if (options.debug || options.onDebug) {
+        const effectiveExitCode = result?.exitCode ?? (err instanceof ExecError ? err.result.exitCode : null);
         const debugInfo: DebugInfo = {
           command,
           args,
           pid: child.pid ?? undefined,
-          exitCode: result?.exitCode ?? (err instanceof ExecError ? err.result.exitCode : null),
+          exitCode: effectiveExitCode,
           exitSignal,
           durationMs,
           stderrLength: stderr.length,
           stdoutLength: stdout.length,
+          noisySuccess: effectiveExitCode === 0 && stderr.length > 0,
         };
         options.onDebug?.(debugInfo);
       }

tools/ai-cli-dispatch/src/types.ts

@@ -24,6 +24,7 @@ export interface DebugInfo {
   durationMs: number;
   stderrLength: number;
   stdoutLength: number;
+  noisySuccess: boolean;
 }
 
 export interface DispatchConfigFile {

tools/ai-cli-dispatch/tests/execute.test.ts

@@ -320,4 +320,46 @@ describe("executePrompt", () => {
     assert.strictEqual(debugInfos[0].exitCode, null);
     assert.strictEqual(debugInfos[0].exitSignal, null);
   });
+
+  it("reports noisySuccess=true when stderr is non-empty and exitCode is 0", async () => {
+    const scenarios = new Map<string, MockScenario>([
+      ["codex exec --yolo hello", { stdout: "ok", stderr: "warn", exitCode: 0 }],
+    ]);
+    const debugInfos: any[] = [];
+    await executePrompt("codex", "hello", {
+      spawn: mockSpawn(scenarios),
+      existsSync: () => true,
+      debug: true,
+      onDebug: (info) => debugInfos.push(info),
+    });
+    assert.strictEqual(debugInfos[0].noisySuccess, true);
+  });
+
+  it("reports noisySuccess=false when stderr is empty and exitCode is 0", async () => {
+    const scenarios = new Map<string, MockScenario>([
+      ["codex exec --yolo hello", { stdout: "ok", stderr: "", exitCode: 0 }],
+    ]);
+    const debugInfos: any[] = [];
+    await executePrompt("codex", "hello", {
+      spawn: mockSpawn(scenarios),
+      existsSync: () => true,
+      debug: true,
+      onDebug: (info) => debugInfos.push(info),
+    });
+    assert.strictEqual(debugInfos[0].noisySuccess, false);
+  });
+
+  it("reports noisySuccess=false when exitCode is non-zero even if stderr is non-empty", async () => {
+    const scenarios = new Map<string, MockScenario>([
+      ["codex exec --yolo fail", { stdout: "", stderr: "error", exitCode: 1 }],
+    ]);
+    const debugInfos: any[] = [];
+    await executePrompt("codex", "fail", {
+      spawn: mockSpawn(scenarios),
+      existsSync: () => true,
+      debug: true,
+      onDebug: (info) => debugInfos.push(info),
+    });
+    assert.strictEqual(debugInfos[0].noisySuccess, false);
+  });
 });