Fix: show deleted worktree, related to issue 945

[swellee]

added: use-deleted-worktrees.ts, to gather deleted worktree paths from tasks;
modified: worktree-list, show deleted worktrees;

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 76 lines in your changes missing coverage. Please review.
✅ Project coverage is 15.88%. Comparing base (5be99bc) to head (c1579b6).

Files with missing lines	Patch %	Lines
...ages/vscode-webui/src/components/worktree-list.tsx	0.00%	54 Missing ⚠️
...scode-webui/src/lib/hooks/use-deleted-worktrees.ts	0.00%	21 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (75.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #980      +/-   ##
==========================================
- Coverage   15.90%   15.88%   -0.03%     
==========================================
  Files         576      577       +1     
  Lines       52884    52958      +74     
  Branches     1704     1702       -2     
==========================================
  Hits         8411     8411              
- Misses      44236    44309      +73     
- Partials      237      238       +1     

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[wsxiaoys]

#945