feat: worktree status, PR checks, action improvements

[egor-xyz]

Summary

• Show git status badges (modified/ahead/behind) on worktree rows, same as main project item
• Add loading state with spinner and disabled buttons when deleting a worktree
• Add "Hide completed actions" setting — always shows running actions without limits
• Move ignore/hide workflow into a dropdown menu (caret-down) on action rows
• Show PR check status (pass/fail/pending) on pull request items like GitHub UI
• Add copy action GitHub link button with green tick feedback

Test plan

• Verify worktree rows show modified/ahead/behind badges
• Verify deleting a worktree shows spinner and disables buttons
• Enable "Hide completed actions" in Settings → GitHub and verify only running actions show
• Verify action row dropdown menu contains "Hide this action" and "Ignore workflow"
• Verify "Ignore workflow" shows confirmation dialog
• Verify PR items show check status icons with tooltip
• Verify copy link button shows green tick after clicking

🤖 Generated with Claude Code