fix(env): preserve main compatibility after stack sync

Author: liangmiQwQ

crates/vp_global_cli/src/cli.rs

@@ -673,7 +673,6 @@ async fn run_package_manager_command(
         None => {}
     }
 
-    let hint_command = command.clone();
     let selected = commands::env::package_manager::resolve_current_spec(&cwd).await?;
     let result = match selected {
         Some(selected) => {

crates/vp_pm_cli/src/dispatch.rs

@@ -100,7 +100,8 @@ async fn dispatch_with_manager(
 }
 
 fn package_manager_from_environment(cwd: &AbsolutePath) -> Result<Option<PackageManager>, Error> {
-    let Some(spec) = vp_shared::EnvConfig::get().package_manager else {
+    let config = vp_shared::EnvConfig::get();
+    let Some(spec) = config.package_manager.as_deref() else {
         return Ok(None);
     };
     let Some((name, version)) = spec.trim().split_once('@') else {