#3946 fix(a11y): give DataTable row action buttons an accessible name

Summary

Icon-only row action buttons in DataTable had no accessible name. Screen readers announced them as "button":

• Buttons with a title only linked it via aria-describedby. That is a description, not a name.
• Several actions had no title at all: app settings, bundle settings and delete, channel delete, and member remove. The channel settings action also returned an empty title when the user could read the channel.

Changes:

• TableAction.title is now required, so TypeScript flags any action without one.
• The row action button uses the title as its aria-label. The visual tooltip is kept and marked aria-hidden, so it is not announced twice.
• I added the missing titles using existing i18n keys (settings, delete, remove), so no new strings.

Test plan

• bun run typecheck and eslint on the changed files pass.
• Members page on a local seed (admin@capgo.app): before the fix, 6 visible row action buttons had no accessible name in 3 out of 3 loads. After the fix, 0 out of 3. Checked with a Playwright assertion on main td button.

🤖 Generated with Claude Code

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Summary by CodeRabbit

• Accessibility
  • Action buttons now provide descriptive accessible names, making their purpose clearer to screen-reader users.
• Bug Fixes
  • Settings, delete, and remove actions now display translated labels as tooltips where applicable.
  • Channel settings continue to show a permission message when the user cannot read the channel; the delete action now consistently identifies itself as “Delete.”