[BUG] Claude Desktop: Pinned projects become undismissable zombies in sidebar after the underlying project is deleted

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

When a project is deleted from Claude Desktop, it remains pinned in the sidebar's Pinned section. Since the underlying project record is already gone, the app can no longer track or act on that sidebar entry:

• Unpin action has no effect (or is unavailable)
• Delete action has no effect (or is unavailable)
• The entry persists across app restarts as a "zombie" — visible but unactionable

This is distinct from existing related issues:

• #33502 — concerns the "Recent" list, not the "Pinned" section
• #42242 (closed, dup of #26960) — concerns orphaned Code sessions whose cwd disappeared, not pinned projects

The Pinned section appears to have its own persistence layer that is not garbage-collected when the source project is deleted.

What Should Happen?

One of:

1. Automatic cleanup: when a project is deleted, its pinned-sidebar reference is removed as part of the deletion transaction.
2. Manual escape hatch: allow the user to unpin / remove sidebar entries even when the backing project no longer exists (right-click → "Remove from sidebar", or similar).
3. Visual indicator + one-click removal: mark orphaned pinned items as stale and provide an inline "×" to dismiss.

Steps to Reproduce

1. Open a project in Claude Desktop.
2. From the project view, click the top-right "..." menu → Pin. The project now appears in the sidebar's Pinned section.
3. From the same project view, click the top-right "..." menu → Delete. The project is deleted.
4. The pinned entry remains in the sidebar (not auto-removed).
5. Click the zombie pinned entry → a "not found"-style error appears (displayed in English, even on a non-English locale).
6. Click the "..." on the zombie sidebar entry → menu appears with Unpin and Delete options.
7. Click Unpin → same "not found" error, entry is not removed.
8. Click Delete → same "not found" error, entry is not removed.
9. Quit and relaunch Claude Desktop → the zombie entry persists in the sidebar.

Error Messages / Logs

• UI shows a "not found" error (exact text not captured verbatim; shown in English).
• App logs not yet inspected.

Environment

• Claude Code version: 2.1.114
• macOS: 26.5 (build 25F5042g)
• Platform: Anthropic API (Claude Max)

Is this a regression?

Unknown — first time observing this behavior.

Additional Context

Related issues for cross-reference:

• #33502 (FEATURE: delete from Recent list)
• #42242 / #26960 (orphaned Code sessions)
• #13514 (general session-deletion feature request)

The present report is narrower: specifically the Pinned section's state becoming orphaned after project deletion, with no UI-level recourse.