Fix the control plane for the line-number gutter: M-x
window.toggle-line-numbers now works from EITHER frontend, each affecting
its own window.
Root cause (scores framing bet Q#UX1 false): rendering a gutter is
frontend-local, but the TOGGLE is a daemon command, so the mode has to
reach the GUI over the wire. My earlier GPU control (a --line-numbers flag)
left M-x-in-the-GUI a no-op and the two frontends' settings disconnected.
- Protocol: new additive `InstanceMessage::LineNumbers { buffer_id,
enabled }`; PROTOCOL_VERSION 12 → 13, SUPPORTED grows to [6..13].
Daemon-gated < 13 (a v12 peer keeps its gutter off), like every prior
additive bump — no encoding break.
- Producer: SemanticRenderState::line_numbers_msg reads the frontend's
active window mode (via active_window_for(frontend_id)) and emits on
change; cached-compare suppression seeded to the frontend's `off`
default, so a plain window adds zero traffic and existing frames are
unchanged.
- Daemon: gate LineNumbers >= 13 in the write loop.
- TUI: drops LineNumbers silently (reads its window directly).
- GPU: consumes LineNumbers → drives local `line_numbers`; the
--line-numbers flag retired.
Now the daemon Window.line_numbers is the single source of truth; both
frontends render locally from it.
Tests: line_numbers_msg emit-on-toggle/suppress-when-unchanged; protocol
version pins updated to 13. Validated: fmt + clippy --all-targets clean
both flavors; 1440 lib + 12 protocol + 53 pmacs-gpu tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014TXbAwk27agwhrNNrhLi2U
