feat(app): add delete button for sessions in sidebar

[achmalll]

Issue for this PR

Closes #33129

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Adds a delete (trash) icon button next to the existing archive button on each root session row in the project/session sidebar (legacy/prod layout).

Clicking the trash icon opens a confirmation dialog. After confirming, the app calls the existing client.session.delete API to permanently remove the session. If the deleted session is currently active, the user is redirected to the next session or the new-session view.

The implementation intentionally reuses existing patterns (archiveSession, useDialog, Dialog, IconButton, i18n strings, and the trash icon) to keep the change small and consistent.

How did you verify your code works?

I ran the following locally:

bun install
bun run --cwd packages/app typecheck
bun lint

I also manually tested the legacy sidebar: hovered over a session, clicked the trash icon, confirmed the dialog, and verified the session is removed from the list.

Screenshots / recordings

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍