When user explicitly sets --headed false, the CLI was ignoring this
flag because the launch condition only checked if flags.headed was
true. This meant that --headed false would not trigger a launch
command, and subsequent commands would auto-launch with default
headless=true.
The fix adds a cli_headed flag to track when the user explicitly
sets --headed (regardless of value), and includes this in the
launch condition check.
Fixes#743
