fix(agent): v0.3.10 cleanup orphan instance dirs on startup

- Add cleanupOrphanInstanceDirs() to remove leftover instance directories
  after failed deletes (common on Windows when compose.log is locked)
- Log RemoveAll errors in dockerComposeRm for better visibility
- Bump version to 0.3.10 and rebuild binaries

agent/docker.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -92,7 +93,11 @@ func dockerComposeRm(dataDir, instanceID string) error {
 	if err := cmd.Run(); err != nil {
 		return err
 	}
-	return os.RemoveAll(dir)
+	if err := os.RemoveAll(dir); err != nil {
+		log.Printf("dockerComposeRm: failed to remove %s: %v (will retry on next startup)", dir, err)
+		return err
+	}
+	return nil
 }
 
 // extractPublicURL tries to find the public URL from a WordPress compose config.