issue 4531 slice 76: PublishingShell rename an edition #5202

Parent: #4531

Slice goal

In PublishingShell Design, an admin renames one edition. The edition list shows the new name only after save. Priority, comment, and content-list order stay as they were.

Out of scope

Create, copy, delete, reorder content lists, and changing priority or comment. #1371 UAT and JSF page deletes.

Acceptance criteria

• Rename via the existing edition update (name only): WebUI Design + Vitest + H2 surface Playwright + product-docs/8.2.
• Blank or over-long name is rejected on the client and does not call save.
• Cancel keeps the old name. HTTP 400, 403, and 409 keep the old name.
• After success the list shows the new name and the same content-list order and priority.
• Update parent [8.2] Unified publishing — next React increments #4531 Agent progress.

Leave unassigned. Do not add In Progress.

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