[Feature Request] TUI gutter and trailing padding make copy-paste tedious

Bug Description
TUI left gutter makes copy-paste tedious

Claude Code renders every line of assistant output with a 2-space left margin (the visible gutter). When I select text in the terminal, those 2 spaces are included in the copy, so every pasted line starts with . Same issue exists with trailing padding to terminal width — lines come out with trailing whitespace too.

I copy content out of Claude Code often (codding tools, code snippets, explanations to paste into PRs / Linear / Slack) and having to strip leading+trailing whitespace every time is a real friction point.

Example: this message

Tried:

• JetBrains embedded terminal → switched to Konsole (KDE). Same behavior, so it's the renderer, not the terminal.
• Konsole's "Trim trailing spaces on copy" helps with trailing, but there's no equivalent for leading.
• No setting in ~/.claude/settings.json, no env var, no CLI flag found.

Request: either

1. A setting to disable the left gutter / render flush-left (e.g. "tui": { "gutter": false } or "compactOutput": true), or
2. A "copy-friendly" render mode that drops both the gutter and trailing line padding, or
3. At minimum, don't pad lines to terminal width so trailing whitespace isn't in the buffer.

Env: Claude Code CLI on openSUSE Linux, Konsole (KDE) and JetBrains terminal both affected.