expand $VAR references in env file values and sandbox paths

internal/sandbox/config.go

@@ -110,7 +110,7 @@ func expandPath(pattern, cwd string) string {
 		return match
 	})
 
-	s = paths.ExpandHome(s)
+	s = paths.ExpandHome(os.ExpandEnv(s))
 	return s
 }
 

pkg/env/env.go

@@ -84,7 +84,7 @@ func LoadFile(path string) {
 		}
 		v = strings.TrimSpace(v)
 		if k != "" && os.Getenv(k) == "" {
-			os.Setenv(k, paths.ExpandHome(v)) //nolint:errcheck
+			os.Setenv(k, paths.ExpandHome(os.ExpandEnv(v))) //nolint:errcheck
 		}
 	}
 }