fix(tui): increase permission dialog height for better code review

[ThanhNguyxn]

Summary

Fixes #7091

The permission dialog's diff view was limited to 1/4 of the terminal height, making it difficult to review code changes before approving.

Changes

Changed maxHeight from Math.floor(dimensions().height / 4) to Math.floor(dimensions().height / 2) in permission.tsx, doubling the available space for code review.

Before/After

• Before: Diff view takes 25% of terminal height
• After: Diff view takes 50% of terminal height

This makes it much easier to review larger diffs before approving permission requests.

File Changed

• packages/opencode/src/cli/cmd/tui/routes/session/permission.tsx