Default chat input height to 2-3 lines for better click target on HD/4K displays

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

On HD/4K displays, the chat input area is a single-line click target that is very small on HD and especially difficult on 4K screens. This creates repeated UX friction because:

Focus frequently is lost as people work across apps. The effort to return to Claude and continue chatting requires a very precise mouse click on a very small target.
The tooltip hover effects from the adjacent "more options" and "Auto accept..." buttons create hint boxes that overlay and obscure the input area, compounding the above issue.

Proposed Solution

The input area defaults to 2 or 3 lines of height or has a setting to let users change the default number of lines; which provides a larger click target needed on 4K; ensures tooltips don't hide the clickable chat/text area.

Alternative Solutions

A configurable setting in settings.json (e.g., inputLines: 3) would let users adapt to their display without changing the default for everyone.

Priority

Low - Nice to have

Feature Category

Other

Use Case Example

Developer on a 4K display switches between VS Code, browser, and Claude Code frequently throughout the day. Each return to Claude requires a precision click on a tiny single-line input. Tooltips from adjacent buttons often obscure the target, requiring multiple attempts. Defaulting to 2-3 lines eliminates this friction entirely.

Additional Context

_No response_