[FEATURE] Desktop app Code tab: cap conversation column max-width for readability on wide windows

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

In the Claude Desktop app's Code tab, the conversation column has no maximum width. It stretches to fill whatever horizontal space is available, which produces extremely long line lengths on wide windows. Readability drops sharply once lines exceed ~80-120 characters.

This forces a bad tradeoff:

• Narrow the window to get comfortable line length → no room to open the left sidebar (projects/conversations) or the right pane (diffs, file previews, terminal output) without the conversation column becoming cramped
• Widen the window to fit sidebars and right pane → conversation text becomes near-unreadable mega-long lines

For comparison, the Codex desktop app caps the conversation column at a sensible max-width and centers it. This means a user can run a wide window with both sidebars open, and the conversation in the middle stays readable. Whitespace flanks the column instead of stretched text.

This is specifically about the Code tab in Claude Desktop (where Claude Code runs), not the CLI/terminal version of Claude Code. Related but distinct from #28326, which requests the same cap for the terminal version.

Related:

• #28326 - Same problem, but for the CLI/terminal version of Claude Code
• #48887, #48237, #50543 - Adjacent Code-tab readability issues (font size, not column width)

Environment:

• Platform: macOS / Windows (issue exists on both)
• App: Claude Desktop
• Tab affected: Code

Proposed Solution

Cap the conversation column at a readable max-width (something around 720-820px / ~80-100 characters at default font size) and center it within the available space.

Ideally:

• Sensible default that works out of the box, no config needed
• Optional setting to adjust the max-width (or disable the cap) for users who prefer the current behavior
• Same behavior in Chat and Cowork tabs if they have the same issue

The whole point of a desktop app over the CLI is being able to use the extra horizontal real estate for context (sidebars, previews, diffs). Without a max-width cap, that extra real estate actively hurts the core experience (reading the conversation) instead of helping.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

Example scenario:

1. I'm working in the Code tab of Claude Desktop on my 14" MacBook Pro
2. To get a comfortable reading width for Claude's responses, I narrow the app window so the conversation column matches readable line length (~80-120 characters)
3. Now I want to open the left sidebar (recent conversations) or the right pane (diffs, file previews) - but the window is too narrow to fit them alongside the conversation
4. So I widen the entire app window to make room for the side panels
5. When I later close the panel, or switch to a conversation without an open panel, the conversation column stretches to the full window width again and becomes uncomfortably wide to read
6. I'm stuck constantly resizing the whole app window depending on whether panels are open or closed

With a max-width cap on the conversation column (similar to how the Codex desktop app handles this), the column would stay at a readable width regardless of window size. I could open and close side panels freely without ever needing to touch the window size - the conversation stays readable, and panels get the space they need.

Additional Context

_No response_