[Bug] Taxonomy page: a long tag name joined with underscores or without spaces does not wrap and overflows the tag list #869

Environment: Master Sandbox, https://apps.master.openedx.io/
Steps to reproduce

1. Download the taxonomy export file QA758 Closed Taxonomy 13.10 (1).csv.
2. In Studio, go to Taxonomies and import the file as a new taxonomy with Tags taxonomy type.
3. Open the imported taxonomy. It contains two 235-character tags made of the same 20 words: one joined with underscores (Competency_Framework_Assessment_..._Strategic_Technical) and one joined with hyphens (Competency-Framework-Assessment-...-Strategic-Technical). The other tags in the file come from other test scenarios. The two names that start with 255 A characters overflow too, because they contain no separator at all, which is not a realistic case.

Actual result

• The hyphen-joined name wraps at the hyphens and fits inside the Tag name column (7 lines at a column width of 358 px).
• The underscore-joined name and name without spaces stay on a single line about 1,650 px wide. It overlaps the tag's action menu button (⋮) and runs underneath the Taxonomy details panel.
• At a 1366 px window width, the underscore-joined name and name without spaces also adds a horizontal scrollbar to the whole page (page width 1696 px, visible width 1351 px).

Expected result

A long tag name wraps inside the Tag name column regardless of which separator it uses, so that it does not overlap the action menu button or the Taxonomy details panel, and does not cause horizontal page scrolling. Names that use underscores are realistic in imported frameworks, where tags often mirror snake_case codes or identifiers.

Technical notes

• The tag name is rendered in src/taxonomy/tag-list/tagColumns.tsx as a <span> inside <span className="d-flex align-items-center gap-2">. This markup was introduced in frontend-app-authoring PR #2872.
• The table cell already has overflow-wrap: break-word, but the text does not break. A likely cause is that the inner <span> is a flex item, and a flex item defaults to min-width: auto, so it cannot shrink below the width of its longest unbreakable word. Browsers treat a hyphen as a line-break opportunity, but not an underscore. Adding min-width: 0 to that <span>, or using overflow-wrap: anywhere, would probably fix it. This cause has not been confirmed in code.
• The issue was found during QA of [BE] Implement the external_id not nullable constraint as described in openedx_tagging ADR 12 #758, but it is not caused by [BE] Implement the external_id not nullable constraint as described in openedx_tagging ADR 12 #758, which changes no frontend code.