[FEATURE] Fullscreen renderer: let me copy a single table cell

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

When Claude's answer has a markdown table, I usually need one value out of it, like a command, a path or a number. Mouse selection picks whole lines, so I get the entire row with the │ borders and padding, and I have to clean it up by hand.

On the default renderer I can get around this with kitty's rectangle selection (Ctrl+Alt+drag), which grabs just the cell. On the fullscreen renderer that doesn't work, and fullscreen is the renderer I use because copy-on-select and mouse support only exist there. So in fullscreen there is no clean way to copy one cell

Proposed Solution

Let a table cell be selected on its own in the fullscreen renderer. Either of these would do it:

1. Double-click inside a table cell selects only that cell's text, without the borders or padding, with a wrapped cell joined back into one line.
2. Alt+drag does a rectangular (block) selection in Claude Code's own selection, like most terminals have.

Option 1 is the nicer one, since the renderer already knows where each cell starts and ends

Alternative Solutions

• Switch to /tui default and use the terminal's rectangle selection. Works, but I lose copy-on-select and mouse support.
• Ask Claude to put the values in code blocks instead of a table. Works, but I have to remember to ask every time.
• Copy the whole row and delete the rest by hand. This is what I do now

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

Claude answers with a table of packages and their install commands. I want the command from the third row so I can paste it into another terminal. In fullscreen I can only copy the whole line, borders and padding included, and then trim it down to the command

Additional Context

• Claude Code 2.1.296, kitty 0.48.2, Arch Linux, /tui fullscreen
• Related but not the same: #37796 and #18170 (copied text picks up extra indentation and trailing spaces)