Add `global.copy` to the TUI keymap schema, runtime keymap,
and interactive remap action list so the Copy shortcut can be
remapped or unbound like other global shortcuts.
Move the existing `ctrl-o` default into a new `v3` preset while
preserving older presets, and update docs plus coverage for the
remapped copy behavior.
Preserve mainline submit/queue semantics, update approval tests for
`SubmitThreadOp`, and keep permission-deny shortcuts from shadowing
`Esc` cancellation.
Add a `v2` keymap preset so `latest` can restore `alt-d`
`delete_forward_word` without mutating frozen `v1` defaults, and refresh
the generated config schema and docs.
Make shifted letter bindings robust when terminals report uppercase
letters without explicit SHIFT modifiers.
This updates keybinding matching so bindings like `shift-i`, `shift-a`,
and `shift-o` also match `I`, `A`, and `O` event forms, and adds
regression tests covering Vim normal-mode actions for line-start insert,
line-end append, and open-line-above with shift-only bindings.
Expose Vim bindings through the TUI keymap config and add a startup
toggle so Vim mode can be enabled by default.
Wire runtime keymap handling for Vim actions, add
`tui.vim_mode_default` to config parsing/runtime config, apply the
default in ChatWidget startup paths, and update docs/default
keymap/schema accordingly.
Publish keymap system documentation first so the implementation stack can
be reviewed against explicit behavior and invariants.
This commit adds the keymap system guide, action matrix, default keymap
template, and config/example documentation updates, plus a rollout plan
used to stage the additive refactor and validation work.
