fix(cli): return JSON from agent logs (#8589)

* fix(cli): print JSON from paseo logs --json

paseo logs ignored the global --json flag and always printed the text
transcript. Print { agentId, items } for one-shot logs, and one timeline
item per line in --follow mode, with the follow notices on stderr so
stdout stays parseable.

* fix(cli): honor the JSON format alias in agent logs

Verify JSON output through the real CLI and isolated daemon, including the documented --format json spelling.

Co-authored-by: hadan8977 <zc-huang23@mails.tsinghua.edu.cn>

* test(cli): verify JSON follow history and live output channels

* fix(cli): stop JSON log followers when their reader closes at startup

Observe shutdown before saved history is written and retain an early stop through subscription setup. Dispose listeners and the subscription on every follow exit.

* fix(cli): interrupt pending log follow startup

Race history and subscription setup against shutdown so Ctrl+C does not wait for a slow daemon response.

---------

Co-authored-by: hadan8977 <zc-huang23@mails.tsinghua.edu.cn>
Co-authored-by: paseo-bot[bot] <266920839+paseo-bot[bot]@users.noreply.github.com>

packages/cli/src/utils/wait-for-stop.ts

@@ -3,9 +3,10 @@
 // their output closes its end, as `| head` does. A closed reader shows up as
 // EPIPE on the next write to stdout, so the command stops at its next line of
 // output.
-export function waitForStop(): Promise<void> {
+export function waitForStop(signal?: AbortSignal): Promise<void> {
   return new Promise((resolve) => {
     const stop = () => {
+      signal?.removeEventListener("abort", stop);
       process.off("SIGINT", stop);
       process.off("SIGTERM", stop);
       process.stdout.off("error", stopOnClosedStdout);
@@ -20,5 +21,7 @@ export function waitForStop(): Promise<void> {
     process.on("SIGINT", stop);
     process.on("SIGTERM", stop);
     process.stdout.on("error", stopOnClosedStdout);
+    signal?.addEventListener("abort", stop, { once: true });
+    if (signal?.aborted) stop();
   });
 }