Closes bd-3ny. Added mousedown listener that dismisses the dropdown when
clicking outside both the dropdown and textarea. Uses early return to avoid
registering listeners when dropdown is already closed.
Adds comprehensive test coverage for the amc_server package:
- test_context.py: Tests _resolve_zellij_bin preference order (which
first, then fallback to bare name)
- test_control.py: Tests SessionControlMixin including two-step Enter
injection with configurable delay, freeform response handling,
plugin inject with explicit session/pane targeting, and unsafe
fallback behavior
- test_state.py: Tests StateMixin zellij session parsing with the
resolved binary path
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
