Lift line coverage back over the 95% floor after the Flutter 3.44.1
merge nudged it to 94.99%. Adds tests for the changeWord/no-op-edit/
empty-paste/word-motion-edge branches in vim_edit_ops, the lone-key
flush path in SequenceMatcher, and the keybindings-ui / vim extension
identity + deactivate paths.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
T-65 — the capstone of the Vim epic. assets/keymaps/vim.yaml binds the
muscle-memory set guarded on vim.normal/insert/visual: hjkl/w/b/e/0/$/^/
gg/G motions, x/dd/dw/D/yy/p/P/cc/cw edits, i/a/I/A/o/O insert entries,
v + d/y/c in visual, Esc back to normal, and counts via the matcher. App
shortcuts (palette, find, zoom) are carried in the preset so they survive
under Vim.
The editor now feeds Shift chords to the matcher (Vim's capitals: G, D,
A, P, $) while still bubbling Ctrl/Alt/Meta to the global handler. The
keybindings-ui stub gains palette commands (`Keymap: Vim` / `Keymap:
Default`) to switch presets — the user-facing way to turn Vim on.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>