[FEATURE] Word-jump cursor navigation in Chat input (option+arrow / bindable actions)

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The Chat input widget has no word-by-word cursor navigation. On macOS, option+left / option+right are the standard shortcuts for jumping one word at a time — they work in every terminal app and editor, but not in Claude Code's Chat input. The keybindings system also exposes no word-movement actions (chat:wordLeft / chat:wordRight), so there's no workaround via ~/.claude/keybindings.json.

This forces users to either hold arrow keys or use the mouse to reposition the cursor mid-sentence, which is disruptive to typing flow.

Proposed Solution

Add word-jump actions to the Chat context:

• chat:wordLeft — move cursor one word backward (default: option+left)
• chat:wordRight — move cursor one word forward (default: option+right)
• Optionally: chat:deleteWordRight to complement the existing ctrl+w (delete word left)

All actions should be bindable via ~/.claude/keybindings.json.

Alternative Solutions

• ctrl+w deletes a word backward but provides no movement-only equivalent
• No workaround exists for forward word movement
• External editor (ctrl+g) works but is heavyweight for a one-word cursor fix

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

1. Typing a long prompt, notice a typo two words back
2. Want to jump back with option+left twice, fix it, jump forward
3. Currently: must hold ← or use mouse — breaks typing flow

Additional Context

Related: the keybindings docs at https://code.claude.com/docs/en/keybindings list all available actions — word-jump is absent from the Chat context actions entirely.