refactor: Add CleanupStatus type to replace raw strings (gt-77gq7)

Introduces a typed CleanupStatus with constants:
- CleanupClean, CleanupUncommitted, CleanupStash, CleanupUnpushed, CleanupUnknown

Adds helper methods:
- IsSafe(): true for clean status
- RequiresRecovery(): true for uncommitted/stash/unpushed
- CanForceRemove(): true if force flag can bypass

Updated files to use the new type:
- internal/polecat/types.go: Type definition and methods
- internal/polecat/manager.go: Validation logic
- internal/witness/handlers.go: Nuke safety checks
- internal/cmd/done.go: Status reporting
- internal/cmd/polecat.go: Recovery status checks

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/polecat/types.go

@@ -78,3 +78,48 @@ func (p *Polecat) Summary() Summary {
 		Issue: p.Issue,
 	}
 }
+
+// CleanupStatus represents the git state of a polecat for cleanup decisions.
+// The Witness uses this to determine whether it's safe to nuke a polecat worktree.
+type CleanupStatus string
+
+const (
+	// CleanupClean means the worktree has no uncommitted work and is safe to remove.
+	CleanupClean CleanupStatus = "clean"
+
+	// CleanupUncommitted means there are uncommitted changes in the worktree.
+	CleanupUncommitted CleanupStatus = "has_uncommitted"
+
+	// CleanupStash means there are stashed changes that would be lost.
+	CleanupStash CleanupStatus = "has_stash"
+
+	// CleanupUnpushed means there are commits not pushed to the remote.
+	CleanupUnpushed CleanupStatus = "has_unpushed"
+
+	// CleanupUnknown means the status could not be determined.
+	CleanupUnknown CleanupStatus = "unknown"
+)
+
+// IsSafe returns true if the status indicates it's safe to remove the worktree
+// without losing any work.
+func (s CleanupStatus) IsSafe() bool {
+	return s == CleanupClean
+}
+
+// RequiresRecovery returns true if the status indicates there is work that
+// needs to be recovered before removal. This includes uncommitted changes,
+// stashes, and unpushed commits.
+func (s CleanupStatus) RequiresRecovery() bool {
+	switch s {
+	case CleanupUncommitted, CleanupStash, CleanupUnpushed:
+		return true
+	default:
+		return false
+	}
+}
+
+// CanForceRemove returns true if the status allows forced removal.
+// Uncommitted changes can be force-removed, but stashes and unpushed commits cannot.
+func (s CleanupStatus) CanForceRemove() bool {
+	return s == CleanupClean || s == CleanupUncommitted
+}