feat(progress): humanize subagent updates

src/wrapper/cli.test.ts

@@ -250,6 +250,66 @@ test("wrapper does not exit early on non-terminal toolUse assistant messages", a
   assert.match(eventsText, /"type":"tool_call"/);
 });
 
+test("wrapper skips blank assistant transcript lines before later tool activity", async () => {
+  const dir = await mkdtemp(join(tmpdir(), "pi-subagents-wrapper-"));
+  const metaPath = join(dir, "meta.json");
+  const resultPath = join(dir, "result.json");
+  const transcriptPath = join(dir, "transcript.log");
+  const piPath = join(dir, "pi");
+
+  await writeFile(
+    piPath,
+    [
+      `#!${process.execPath}`,
+      "console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'   '}],model:'openai/gpt-5',stopReason:'toolUse'}}));",
+      "setTimeout(() => console.log(JSON.stringify({type:'tool_execution_start',toolName:'read',args:{path:'src/auth.ts'}})), 100);",
+      "setTimeout(() => console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'done'}],model:'openai/gpt-5',stopReason:'stop'}})), 200);",
+      "setTimeout(() => process.exit(0), 400);",
+    ].join("\n"),
+    "utf8",
+  );
+  await chmod(piPath, 0o755);
+
+  await writeFile(
+    metaPath,
+    JSON.stringify(
+      {
+        runId: "run-1",
+        mode: "single",
+        task: "inspect auth",
+        cwd: dir,
+        requestedModel: "openai/gpt-5",
+        resolvedModel: "openai/gpt-5",
+        startedAt: "2026-04-09T00:00:00.000Z",
+        sessionPath: join(dir, "child-session.jsonl"),
+        eventsPath: join(dir, "events.jsonl"),
+        resultPath,
+        stdoutPath: join(dir, "stdout.log"),
+        stderrPath: join(dir, "stderr.log"),
+        transcriptPath,
+        systemPromptPath: join(dir, "system-prompt.md"),
+      },
+      null,
+      2,
+    ),
+    "utf8",
+  );
+
+  const wrapperPath = join(dirname(fileURLToPath(import.meta.url)), "cli.mjs");
+  const child = spawn(process.execPath, [wrapperPath, metaPath], {
+    env: { ...process.env, PATH: dir },
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+
+  const exitCode = await waitForExit(child, 2500);
+  assert.equal(exitCode, 0);
+
+  const transcript = await readFile(transcriptPath, "utf8");
+  assert.doesNotMatch(transcript, /\nnull\n/);
+  assert.match(transcript, /Reading src\/auth.ts/);
+  assert.match(transcript, /done/);
+});
+
 test("wrapper exits and writes result.json after terminal output even if the pi child lingers", async () => {
   const dir = await mkdtemp(join(tmpdir(), "pi-subagents-wrapper-"));
   const metaPath = join(dir, "meta.json");