fix(core): LiteLoader 快照仓固定为 repo.mumfrey.com/snapshots（1.10.2 的 repo.url 是 /repo/ 形态，照它会 404）

crates/core/tests/liteloader/install.rs

@@ -172,3 +172,69 @@ fn stacks_on_forge_and_keeps_the_forge_tweak_class() {
         .expect("缺 LiteLoader 本体库");
     assert!(forge_lib < liteloader_lib, "{libraries:?}");
 }
+
+/// **新式 args 的父链**：父版本用 `arguments.game`（没有 `minecraftArguments`）。
+///
+/// 现实里 LiteLoader 只到 1.12.2，碰不到这种父版本；但「追加语义」是这套路线的准入条件，
+/// 两种父版本形状都得钉住——否则哪天上游把老版本清单改成新式，我们会静默丢参数。
+/// 这里用一份**手工夹具**（`--launchTarget forgeclient` 是 Forge 1.13+ 的真实形态）说明：
+/// 父层参数在前、LiteLoader 的 tweakClass 在后，中间不互相覆盖。
+#[test]
+fn new_style_parent_args_are_appended_not_replaced() {
+    const MODERN_PARENT: &str = r#"{
+      "id": "1.12.2-modern-1.0",
+      "inheritsFrom": "1.12.2",
+      "mainClass": "net.minecraft.launchwrapper.Launch",
+      "arguments": {"game": ["--launchTarget", "forgeclient"], "jvm": ["-Dmodern=1"]},
+      "libraries": [{"name": "example:modern:1.0", "url": "https://example.invalid/"}]
+    }"#;
+
+    let temp = TempDir::new("modern-args");
+    let layout = GameLayout::new(temp.path());
+    put_version(&layout, "1.12.2", VANILLA_1122);
+    put_version(&layout, "1.12.2-modern-1.0", MODERN_PARENT);
+
+    let release = liteloader_release("1.12.2-modern-1.0");
+    let plan = LoaderInstallPlan::build(LoaderPlanInput {
+        layout: &layout,
+        release: &release,
+        environment: &Environment::host(),
+        parent_installed: true,
+    })
+    .expect("计划应可组");
+    let engine = engine(temp.path());
+    prefill(&plan.install);
+    let report = block_on(execute(&engine, &plan.install, 4, None)).expect("执行应成功");
+    assert!(report.is_complete(), "{:?}", report.failures(3));
+
+    let mut source = std::collections::BTreeMap::new();
+    source.insert("1.12.2".to_string(), read_version(&layout, "1.12.2"));
+    source.insert(
+        "1.12.2-modern-1.0".to_string(),
+        read_version(&layout, "1.12.2-modern-1.0"),
+    );
+    source.insert(
+        release.version_id.clone(),
+        read_version(&layout, &release.version_id),
+    );
+    let resolved = resolve(&source, &source[&release.version_id]).expect("三层继承应可解析");
+
+    // 父层用的是新式参数：子层没有把 legacy 串写进来，继承后仍然没有。
+    assert!(resolved.minecraft_arguments.is_none());
+    let game = resolved
+        .arguments
+        .as_ref()
+        .expect("arguments")
+        .expand(&Environment::host())
+        .game;
+    let assert_order = |needle: &str| {
+        game.iter()
+            .position(|token| token == needle)
+            .unwrap_or_else(|| panic!("缺 `{needle}`：{game:?}"))
+    };
+    assert!(
+        assert_order("forgeclient")
+            < assert_order("com.mumfrey.liteloader.launch.LiteLoaderTweaker"),
+        "父层参数必须在前：{game:?}"
+    );
+}