Properly render worktrees in files panel

pkg/commands/models/file.go

@@ -18,8 +18,10 @@ type File struct {
 	HasMergeConflicts       bool
 	HasInlineMergeConflicts bool
 	DisplayString           string
-	Type                    string // one of 'file', 'directory', and 'other'
 	ShortStatus             string // e.g. 'AD', ' A', 'M ', '??'
+
+	// If true, this must be a worktree folder
+	IsWorktree bool
 }
 
 // sometimes we need to deal with either a node (which contains a file) or an actual file