8bbb31e075
Drops the ``agent-browser install --with-deps`` step (Chrome for
Testing has no ARM64 build and ships several automation tells)
and uses the apt-installed Chromium across both arches.
``agent-browser`` is wired via three env vars baked into the image:
* ``AGENT_BROWSER_EXECUTABLE_PATH=/usr/bin/chromium`` — every
browser launch picks up the apt binary; no per-call flag needed.
* ``AGENT_BROWSER_USER_AGENT`` — recent stable Chrome 131 Linux UA.
* ``AGENT_BROWSER_ARGS`` — minimal stealth flag set:
``--disable-blink-features=AutomationControlled`` (the most-
checked tell), ``--exclude-switches=enable-automation``,
``--disable-features=IsolateOrigins,site-per-process,Translate,
BlinkGenPropertyTrees``, sane window-size + lang, infobars +
save-password + session-crashed bubbles off.
The ``agent-browser doctor --offline --quick`` step at build time
verifies the binary launches; subsequent runtime calls inherit
the env automatically.
Net: smaller image (no ~150 MB Chrome-for-Testing download),
ARM64-clean, env-driven config so future flag tweaks land without
touching the agent-browser install.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>