fix: preserve LM Studio quant model refs (#71486)

src/plugins/providers.test.ts

@@ -1321,6 +1321,52 @@ describe("resolvePluginProviders", () => {
     expectModelOwningPluginIds("gpt-5.4", ["workspace-openai"]);
   });
 
+  it("preserves LM Studio @iq* quant suffixes when resolving model-owned provider plugins", () => {
+    setManifestPlugins([
+      createManifestProviderPlugin({
+        id: "lmstudio",
+        providerIds: ["lmstudio"],
+        modelSupport: {
+          modelPatterns: ["^qwen3\\.6-27b@iq3_xxs$"],
+        },
+      }),
+    ]);
+    const provider: ProviderPlugin = {
+      id: "lmstudio",
+      label: "LM Studio",
+      auth: [],
+    };
+    const registry = createEmptyPluginRegistry();
+    registry.providers.push({ pluginId: "lmstudio", provider, source: "bundled" });
+    resolveRuntimePluginRegistryMock.mockReturnValue(registry);
+
+    expectModelOwningPluginIds("qwen3.6-27b@iq3_xxs", ["lmstudio"]);
+    expectModelOwningPluginIds("qwen3.6-27b", undefined);
+
+    const providers = resolvePluginProviders({
+      config: {},
+      modelRefs: ["qwen3.6-27b@iq3_xxs"],
+      bundledProviderAllowlistCompat: true,
+    });
+
+    expectResolvedProviders(providers, [
+      { id: "lmstudio", label: "LM Studio", auth: [], pluginId: "lmstudio" },
+    ]);
+    expect(resolveRuntimePluginRegistryMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        onlyPluginIds: ["lmstudio"],
+        config: expect.objectContaining({
+          plugins: expect.objectContaining({
+            allow: ["lmstudio"],
+            entries: {
+              lmstudio: { enabled: true },
+            },
+          }),
+        }),
+      }),
+    );
+  });
+
   it("auto-loads a model-owned provider plugin from shorthand model refs", () => {
     setManifestPlugins([
       createManifestProviderPlugin({