fix(termux): 现代清单的 LWJGL natives 条目也改写为 arm64

1.20.x 把 natives 作为独立库条目（org.lwjgl:lwjgl:3.3.2:natives-linux），
不走 natives 表。Linux/aarch64 上按坐标改写成 natives-linux-arm64，
URL 兜底到阿里云 Maven（Mojang 对 arm64 一律 404）。
真机 1.20.4 的 dry-run：7 个 natives 全部变成 arm64；x86_64 不变。

crates/core/src/game/install/libraries.rs

@@ -39,6 +39,20 @@ pub fn plan(
         if !library.applies(environment) {
             continue;
         }
+        // 现代清单把 natives 作为独立库条目（`org.lwjgl:lwjgl:3.3.2:natives-linux`），
+        // 不是 `natives` 表。Linux arm64 上改写坐标并兜底到 Maven 镜像。
+        if let Some(rewritten) = linux_arm64_native_entry(library, environment) {
+            files.push(PlanFile {
+                role: FileRole::Native,
+                name: rewritten.name,
+                url: rewritten.url,
+                sha1: None,
+                size: None,
+                dest: layout.libraries_dir().join(&rewritten.relative),
+                resource: ResourceKind::Library,
+            });
+            continue;
+        }
         if library.coordinate().is_err() {
             warnings.push(format!("库坐标不合法，已跳过：{}", library.name));
             continue;
@@ -136,6 +150,41 @@ fn library_dest(
     }
 }
 
+/// 现代清单里 LWJGL3 natives 条目的改写结果。
+struct Arm64Native {
+    name: String,
+    relative: PathBuf,
+    url: String,
+}
+
+/// Linux arm64：把 `org.lwjgl:<module>:<version>:natives-linux` 改写成 arm64。
+fn linux_arm64_native_entry(library: &Library, env: &Environment) -> Option<Arm64Native> {
+    if env.os != "linux" || env.arch != "arm64" || !library.name.starts_with("org.lwjgl:") {
+        return None;
+    }
+    let base = library.name.strip_suffix(":natives-linux")?;
+    let mut parts = base.split(':');
+    let group = parts.next()?;
+    let artifact = parts.next()?;
+    let version = parts.next()?;
+    if parts.next().is_some() {
+        return None;
+    }
+    let relative = PathBuf::from(format!(
+        "{}/{artifact}/{version}/{artifact}-{version}-natives-linux-arm64.jar",
+        group.replace('.', "/")
+    ));
+    let url = format!(
+        "{LINUX_ARM64_NATIVES_BASE}{}",
+        relative.to_string_lossy().replace('\\', "/")
+    );
+    Some(Arm64Native {
+        name: format!("{base}:natives-linux-arm64"),
+        relative,
+        url,
+    })
+}
+
 /// 按库声明（或默认）的 Maven 基址拼下载地址。
 fn maven_url(library: &Library, relative: &Path) -> String {
     let base = library
@@ -311,6 +360,35 @@ mod tests {
         );
     }
 
+    #[test]
+    fn modern_lwjgl_native_entry_is_rewritten_to_arm64_maven() {
+        // 1.20.x 的清单把 natives 作为独立条目，分类器写在 name 里。
+        let library = library_with_artifact(
+            r#"{"name":"org.lwjgl:lwjgl:3.3.2:natives-linux",
+                "rules":[{"action":"allow","os":{"name":"linux"}}],
+                "downloads":{"artifact":{"path":"org/lwjgl/lwjgl/3.3.2/lwjgl-3.3.2-natives-linux.jar","url":"https://libraries.minecraft.net/x.jar","sha1":"aa"}}}"#,
+        );
+        let env = Environment {
+            os: "linux".to_string(),
+            os_version: String::new(),
+            arch: "arm64".to_string(),
+            ..environment()
+        };
+        let layout = GameLayout::new("/g/.minecraft");
+        let (files, warnings) = plan(&layout, "1.20.4", &[library], &env);
+        assert!(warnings.is_empty(), "不该有告警：{warnings:?}");
+        assert_eq!(files.len(), 1);
+        assert_eq!(files[0].role.as_str(), "native");
+        assert_eq!(files[0].name, "org.lwjgl:lwjgl:3.3.2:natives-linux-arm64");
+        assert_eq!(
+            files[0].url,
+            "https://maven.aliyun.com/repository/public/org/lwjgl/lwjgl/3.3.2/lwjgl-3.3.2-natives-linux-arm64.jar"
+        );
+        assert!(files[0]
+            .dest
+            .ends_with("libraries/org/lwjgl/lwjgl/3.3.2/lwjgl-3.3.2-natives-linux-arm64.jar"));
+    }
+
     #[test]
     fn linux_x86_64_keeps_the_manifest_classifier() {
         let library = library_with_artifact(