opencode feat(tui): add vi basic mode extension for prompt and editor

Summary

A modular vi mode implementation for the OpenCode TUI prompt with support for standalone editors.

Provides the vi extension for prompt but also for the Project Files Viewer and Editor https://github.com/anomalyco/opencode/pull/7017

Core Features

Normal/insert modes with standard vi keybindings
Movement: h/j/k/l, w/b/e, 0/$, G, {/}, %, g{n}g, ctrl+f/b
Delete: x, {n}x, dd, d{n}d, dw, d{n}w, D, d$, dG, d{n}G
Change: cc, c{n}c, cw, c{n}w, C, s
Yank: yy, y{n}y, y$, yG, y%, y{, y}
Paste: p/P (line-wise or character-wise)
Multiline: o, O, J
Other: r, ~, ., u, ctrl+r
Search: /, ?, n, N (with regex support)
Search operators: d/, d?, c/, c?, y/, y?

Configuration

prompt_vi_basic KV setting to enable/disable
vi_basic_clip_x KV setting for clipboard behavior
Toggle via command menu

Architecture

PromptExtension interface for modular prompt extensions
lineNumbers option for gutter redraw (opentui workaround)
Two modes: full (for standalone editors) and prompt (for prompt input)

Files Changed

File	Changes
`lib/vi-basic-core.ts`	Core vi mode logic
`lib/vi-basic-extension.tsx`	Prompt extension wrapper
`lib/prompt-extension.ts`	Extension interface
`component/prompt/index.tsx`	Integration

Jan 06 '26 02:01 ryanwyler

The following comment was made by an LLM, it may be inaccurate:

Duplicate PR Check Results for PR #7016

✅ No duplicate PRs found.

While the search found several related PRs focused on TUI keybindings and navigation, none are duplicates of PR #7016:

Related (but distinct) PRs:

#6448 - feat(tui): [EXPERIMENTAL] Vim-style window system with extensible plugin views - This is a broader vim-style window system, not the specific vi mode keybinding implementation in this PR
#5255 - feat(tui): add ctrl+arrow word navigation in prompt - Word navigation enhancement, different scope
#3888 - feat: add keybindings reference dialog to TUI - Keybindings documentation, not vi mode implementation
#6753 - feat(keybinds): support physical keycode-based keybindings for non-English layouts - General keybinding infrastructure, not vi mode specific

PR #7016 is unique as it implements a modular vi basic mode extension with specific vi keybindings (h/j/k/l, yank, delete, change, search operators, etc.) for the prompt component. This hasn't been addressed in any other open PR.