Use overflow-x clip instead of overflow hidden for truncation

What does this MR do?

gl-truncate and related truncation utilities use overflow: hidden, which clips the bottom of text. Descenders (g, y, p, q, j), box-shadows, and focus rings get cut off.

Solution

Replace overflow: hidden with overflow-x: clip; overflow-y: visible across all truncation utilities and components.

Why overflow-x: clip instead of overflow-x: hidden?

The CSS spec computes overflow-y: visible to auto when paired with overflow-x: hidden, which can create an unwanted scrollbar. When paired with overflow-x: clip, overflow-y: visible stays as visible. This gives us horizontal clipping with ellipsis while letting vertical content (descenders, shadows) render naturally.

We avoid overflow-clip-margin because it is not supported in Safari.

Why min-width: 0?

overflow: hidden creates a block formatting context (BFC), which allows flex children to shrink below their content width. overflow: clip does not create a BFC, so flex children default to min-width: auto and refuse to shrink. Adding min-width: 0 restores the shrinking behaviour without relying on the BFC side-effect.

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Before	After

Integrations

• GitLab: gitlab-org/gitlab!231309 (closed)
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• Duo UI: mr_url
• Status Page: mr_url
• Docs: mr_url
• Switchboard: mr_url

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