add shared pane widgets + Q-023 ssh-remote question

ClidePtyView is a theme-bound wrapper around xterm.dart's TerminalView
— token-derived TerminalTheme, JetBrainsMono as the face, Semantics
live-region label so screen readers + Playwright both hear it. The
consumer (terminal / Claude extensions) owns the `Terminal` model and
wires IPC pane.write / pane.output → terminal.write() themselves; the
widget deliberately has no IPC dependency so it stays trivially
testable.

ClidePaneChrome is the shared pane header — title + subtitle + leading
icon + trailing widgets + optional close button. The close button is
null-conditional so primary Claude panes (D-041, landing in step 7)
can render without one.

xterm 4.0.0 added as a justified runtime dep + logged in
licenses.yaml per D-042. 3 new widget tests cover header rendering,
close-button presence, and the close-tap round-trip.

Q-023 records the SSH-remote-development question so the daemon + IPC
seams don't accrete local-only assumptions during Tier 1-5.

Co-Authored-By: Claude <noreply@anthropic.com>

app/pubspec.yaml

@@ -31,6 +31,12 @@ dependencies:
   # maintained, used for theme files and extension manifests.
   yaml: 3.1.3
 
+  # xterm.dart — Flutter-native terminal emulator (ANSI / xterm / truecolor
+  # parser + renderer). Writing a vt100/ANSI parser that handles everything
+  # tmux / neovim / claude emit would be weeks of work for no fidelity
+  # win. Listed in licenses.yaml per D-042. MIT.
+  xterm: 4.0.0
+
 dev_dependencies:
   flutter_test:
     sdk: flutter