[Requests and ideas] Please add native VIM-style keybindings for everything.

**Mood:** 😔
**Category:** Requests and ideas

Please add native VIM-style keybindings for everything. Prompt editing is the big one, but also general navigation, scrolling, tab switching, reviewing diffs, splits, etc.

---
| Field | Value |
| --- | --- |
| App version | 1.0.0 |
| OS | Ubuntu 24.4.0 |
| Theme | Chai |
| Path | / |
| Tenure | Day 1 |

The issue names no files, tests, or entry points. Start by defining which VIM-style behaviors are in scope beyond prompt editing, including navigation, scrolling, tab switching, diff review, and splits. Done requires agreed acceptance criteria covering the selected areas.

索引モデルが issue の本文から書いたものです。