refactor(enhance): lowercase takes a reference and chain support is copy

use_lowercase borrows the mapping and clones only the values; call
sites no longer clone whole configs. ChainSupport is a fieldless enum
and now Copy; builtin() registers each support pair without clones.

src-tauri/src/enhance/chain.rs

@@ -22,7 +22,7 @@ pub enum ChainType {
     Groups(SeqMap),
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub enum ChainSupport {
     Mihomo,
     MihomoAlpha,
@@ -70,14 +70,11 @@ impl ChainItem {
     /// 内建支持一些脚本
     pub fn builtin() -> Vec<(ChainSupport, Self)> {
         // data intentionally empty: the enhance loop dispatches on uid to native implementations
-        let hy_alpn = Self::to_script("verge_hy_alpn", "");
-        let meta_guard = Self::to_script("verge_meta_guard", "");
-
         vec![
-            (ChainSupport::Mihomo, hy_alpn.clone()),
-            (ChainSupport::Mihomo, meta_guard.clone()),
-            (ChainSupport::MihomoAlpha, hy_alpn),
-            (ChainSupport::MihomoAlpha, meta_guard),
+            (ChainSupport::Mihomo, Self::to_script("verge_hy_alpn", "")),
+            (ChainSupport::Mihomo, Self::to_script("verge_meta_guard", "")),
+            (ChainSupport::MihomoAlpha, Self::to_script("verge_hy_alpn", "")),
+            (ChainSupport::MihomoAlpha, Self::to_script("verge_meta_guard", "")),
         ]
     }
 

src-tauri/src/enhance/field.rs

@@ -24,12 +24,12 @@ fn lowercase_key(key: &str) -> Value {
     Value::from(key.as_str())
 }
 
-pub fn use_lowercase(config: Mapping) -> Mapping {
+pub fn use_lowercase(config: &Mapping) -> Mapping {
     let mut lowercased = Mapping::new();
 
-    for (key, value) in config {
+    for (key, value) in config.iter() {
         if let Some(key_str) = key.as_str() {
-            lowercased.insert(lowercase_key(key_str), value);
+            lowercased.insert(lowercase_key(key_str), value.clone());
         }
     }
     lowercased

src-tauri/src/enhance/merge.rs

@@ -17,7 +17,7 @@ fn deep_merge(a: &mut Value, b: Value) {
 }
 
 pub fn use_merge(merge: &Mapping, mut config: Mapping) -> Mapping {
-    for (key, value) in use_lowercase(merge.clone()) {
+    for (key, value) in use_lowercase(merge) {
         match (config.get_mut(&key), value) {
             (Some(Value::Mapping(existing)), Value::Mapping(overlay)) if key.as_str() == Some("dns") => {
                 existing.extend(overlay);

src-tauri/src/enhance/mod.rs

@@ -614,7 +614,7 @@ fn apply_builtin_scripts(mut config: Mapping, clash_core: Option<String>, enable
             .collect();
         if !items.is_empty() {
             // The JS path saw a lowercased view; lowercase once, only when a builtin runs.
-            config = use_lowercase(config);
+            config = use_lowercase(&config);
             for item in items {
                 logging!(debug, Type::Core, "run builtin script {}", item.uid);
                 config = match item.uid.as_str() {

src-tauri/src/enhance/script.rs

@@ -22,10 +22,10 @@ type EvalOutcome = (Result<Mapping, std::string::String>, Vec<(String, String)>)
 pub(super) async fn use_script(script: String, config: Mapping, name: String) -> ScriptResult {
     // The template is identity-plus-lowercasing; skip the Boa round-trip.
     if script == tmpl::ITEM_SCRIPT {
-        return (use_lowercase(config), vec![], vec![]);
+        return (use_lowercase(&config), vec![], vec![]);
     }
 
-    let json = match serde_json::to_string(&use_lowercase(config.clone())) {
+    let json = match serde_json::to_string(&use_lowercase(&config)) {
         Ok(json) if json.len() <= MAX_JSON_SIZE => json,
         Ok(_) => {
             let message = "Configuration size exceeds maximum allowed size";
@@ -173,7 +173,7 @@ fn eval_script(script: &str, config_json: &str, name: &String) -> EvalOutcome {
     }
 
     match parse_json_safely(&result) {
-        Ok(config) => (Ok(use_lowercase(config)), outputs.lock().to_vec()),
+        Ok(config) => (Ok(use_lowercase(&config)), outputs.lock().to_vec()),
         Err(err) => {
             logging!(
                 error,