## Why
The TUI Vim composer currently diverges from normal Vim editing in two
common workflows: pressing `e` repeatedly can remain stuck at an
existing word end, and normal mode does not support `C` for changing
through the end of the line. The existing `D` behavior also removes the
newline when the cursor is already at the line boundary, which makes the
new `C` action and existing deletion action surprising in multiline
prompts.
Closes#23926.
Closes#24238.
## What Changed
- Make normal-mode `e` advance from the current word end to the next
word end, including for operator motions such as `de`.
- Add configurable Vim normal-mode `change_to_line_end` behavior, bound
to `C` by default, which deletes to the end of the current line and
enters Insert mode.
- Keep the newline intact when `D` or `C` is pressed at the end-of-line
boundary.
- Add regression coverage for repeated `e`, `de`, `C`, and the multiline
`C`/`D` boundary behavior.
- Regenerate the config schema and update the keymap picker snapshots
for the new Vim action.
## How to Test
1. Run Codex with Vim composer mode enabled:
```bash
cd codex-rs
cargo run --bin codex -- -c tui.vim_mode_default=true
```
2. Enter `alpha beta gamma`, press `Esc`, `0`, then press `e`
repeatedly.
Confirm the cursor advances through the ends of `alpha`, `beta`, and
`gamma`.
3. Enter `hello world`, press `Esc`, `0`, `w`, then `C`.
Confirm `world` is deleted and the composer enters Insert mode.
4. Enter a multiline prompt with `hello` above `world`, press `Esc`,
`k`, `$`, and then `D`.
Confirm the newline is preserved and the two lines do not join.
5. At the same boundary, press `C` and type `!`.
Confirm the composer enters Insert mode and yields `hello!` above
`world`, preserving the newline.
Targeted automated verification:
- `just fix -p codex-tui`
- `just argument-comment-lint-from-source -p codex-tui -p codex-config`
- `cargo insta pending-snapshots` reports no pending snapshots.
- `just test -p codex-tui` validates the new Vim and keymap snapshot
coverage, but the command remains red due to two reproducible unrelated
failures in `app::tests::update_feature_flags_disabling_guardian_*`.
## Validation Note
The workspace-wide `just argument-comment-lint` form is currently
blocked during Bazel analysis by the existing LLVM `compiler-rt` missing
`include/sanitizer/*.h` failure; package-scoped source linting for the
changed Rust crates passed.
Felipe Coury
aa184548b1