chore: release v0.3.1

### Fixed
- Orphan cleanup on macOS - TTY comparison now handles macOS '??' format
- Session kill orphan prevention - gt done and gt crew stop use KillSessionWithProcesses

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

internal/cmd/info.go

@@ -74,6 +74,14 @@ type VersionChange struct {
 
 // versionChanges contains agent-actionable changes for recent versions
 var versionChanges = []VersionChange{
+	{
+		Version: "0.3.1",
+		Date:    "2026-01-17",
+		Changes: []string{
+			"FIX: Orphan cleanup on macOS - TTY comparison now handles macOS '??' format",
+			"FIX: Session kill orphan prevention - gt done and gt crew stop use KillSessionWithProcesses",
+		},
+	},
 	{
 		Version: "0.3.0",
 		Date:    "2026-01-17",