macOS: headless launches insert a spurious Google Chrome tile in the Dock

Summary

On macOS, every headless launch inserts a Google Chrome tile into the Dock. Since the tool cold-starts / relaunches the browser per session, the Dock's recent-applications area accumulates duplicate Chrome entries — an icon appears for a browser the user never opened (no window, nothing to interact with).

Environment

• macOS 27.0 (26A428)
• Google Chrome 153.0.8010.37 — system install; agent-browser install was not run (same system-Chrome fallback path as #1607)
• agent-browser 0.26.0
• Launch flags (observed via ps): --headless=new --remote-debugging-port=0 --user-data-dir=<tmp>/agent-browser-chrome-<id> --no-first-run --no-default-browser-check …

Steps to reproduce

1. On macOS with Chrome installed in /Applications (not pinned to the Dock).
2. Run:
   bash复制

   $ agent-browser open about:blank

3. Watch the Dock: a Google Chrome tile is inserted.

Observed (controlled run)

At the exact moment of the launch:

15:08:29.827 launchservicesd: CHECKIN:0x0-0x1df1df 19549 com.google.Chrome
15:08:29.835 Dock: [com.apple.dock:dock-tiles] Inserting tile: <private> at index: 17 for reason: -[DockBar _handleLaunchNotification:data:]
15:08:29.998 Dock: [com.apple.dock:app-state-handler] Launch notification lack value for foreground type key

The headless process registers as "ApplicationType"="BackgroundOnly" in LaunchServices, but the Dock still handles its launch notification and inserts a tile; the logged Dock error suggests the notification is missing the activation/foreground-type value, so the Dock falls back to a regular tile insert.

Accumulation

This doesn't just blink — entries persist and stack:

• defaults read com.apple.dock recent-apps shows repeated Google Chrome entries (observed: 2 duplicates).
• Chrome is not pinned (persistent-apps has no Chrome entry), so all Chrome tiles in the Dock came from these launch events.
• Observed repeatedly in the wild: every session launched through an integration that runs agent-browser … get cdp-url inserts a tile again (7 launches overnight + 3 the next afternoon on one machine, duplicates accumulating each time).

Expected

Launching the browser headless adds nothing to the Dock, and repeated sessions don't accumulate duplicate Chrome entries.

Impact

Cosmetic but user-visible and confusing — a Chrome icon appears with nothing to open, and duplicates must be removed manually from the Dock. No effect on the browsing session itself.

Related

• #1607 — same area (the headless instance lives inside the user's own Chrome app bundle on macOS)