Audit: composer children are not width-constrained (unbounded text can escape the pane) — sibling cases of #95896

Summary

#95896 and #95897 are two instances of the same underlying class of defect in the Code tab composer: content rendered in and around the input box is not width-constrained and the composer is not a clipping container. Filing this as an audit request for the sibling surfaces that share that layout, since a fix scoped only to the struck-through text will likely leave the others broken.

Surfaces worth checking for the same missing min-width: 0 / overflow-wrap / overflow: hidden treatment:

• Queued-message preview — a long queued prompt shown while Claude is working.
• PR / branch chips above the composer — long PR titles, long branch names, long repo names.
• The collapsed "Show N more" chip stack — whether expanding it pushes content past the pane edge.
• Attached-file chips — long file paths and long single-token filenames (no spaces to break on).
• Session title / header — long titles or long working-directory paths.
• Pasted content preview — a pasted long URL or minified line (no break opportunities at all).

The general fixes are the same in each case: min-width: 0 on flex children, overflow-wrap: anywhere (or explicit truncation with a tooltip) on text nodes, and overflow: hidden on the composer/pane container so nothing can paint over window chrome.

I have directly observed only the struck-through case (#95896, #95897); the rest are listed as candidates to audit, not confirmed reports.

Environment

• Claude desktop app 2.2553.1 (macOS 26.5.1), Claude Code CLI 2.1.278