feat(dns): protect provider DNS from unconfirmed overrides (#7902)

Fixes #7292

src-tauri/src/core/manager/config.rs

@@ -138,6 +138,7 @@ impl CoreManager {
         Config::runtime().await.edit_draft(|d| {
             *d = IRuntime {
                 config: Some(clash_config.to_owned()),
+                dns_override: None,
                 exists_keys: HashSet::new(),
                 chain_logs: Default::default(),
             }