Flips the Tier-0 stub into a real extension. Contributes a Terminal
tab in the workspace slot that spawns $SHELL -l via IPC pane.spawn,
feeds pane.output events into xterm.dart's Terminal, and routes user
input back through pane.write. Viewport resize propagates via
pane.resize. Surface for disconnected-daemon / exited-shell states so
there's no silent dead tab.
Knows nothing about Claude deliberately — the Claude-specific pane
(primary-per-repo, tmux-backed, D-041) lives under builtin.claude in
the next steps.
Co-Authored-By: Claude <noreply@anthropic.com>
jpmschweitzerandClaude
e1ea52c5e4