Extend the gutter with the last two of the framed modes (Q#UX4):
- Relative: each line shows its distance from the cursor line (cursor = 0).
- Hybrid: cursor line shows its absolute number, others relative
(Vim number + relativenumber).
`LineNumberMode` gains `Relative`/`Hybrid` + `number_for(line, cursor_line)`
(the per-line displayed value) and `is_on()`. `paint_line_number_gutter`
now derives each number from the mode and the cursor's buffer line
(`text_view.line_at_offset(cursor)`); the TUI re-renders the whole frame on
cursor motion, so relative numbers track the cursor for free. Gutter width
is sized by `digits(line_count)` for every on-mode, so the text never
jitters as the cursor moves.
Mode selection (chosen over a 4-way cycle): `window.toggle-line-numbers`
stays a binary off/absolute toggle; a new `window.set-line-numbers` opens
the minibuffer with an arrow-navigable completion dropdown
(off|absolute|relative|hybrid) to pick a mode directly. `set_line_numbers`
accepts all four; the getter returns them.
No protocol change here — the GPU half (which needs the mode over the wire,
protocol v14) follows. Test: number_for across all modes. fmt + clippy
clean both flavors; 1446 lib tests pass. Needs a TUI eyeball.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014TXbAwk27agwhrNNrhLi2U
Levi Neuwirth
9ae381f740