Third step of the cwd rearchitecture: _resolve_command_cwd now prefers
the session's own cwd record over the shared env's live cwd.
New resolution order: workdir > session record > legacy env.cwd
(ownership-gated, transition-only) > config/override default.
The record is written after every completed command for the session, so
it IS the session's cd state — another session's cd lands in another
record and cannot affect this session's commands. The legacy env.cwd
branch only fires for a session with no record yet (no command has
completed since this code loaded); it keeps the prev_owner ownership
guard for that transition window and is deleted in step 4 along with
env.cwd_owner stamping and file_tools' _last_known_cwd machinery.
Adds command-path regression tests including the terminal sibling of
the leak-A scenario (unowned shared env cwd vs session record) and an
E2E cd round-trip through terminal_tool.
ethernet
fd3d9c63d0