Refactor: Replace all provider split occurrences with getModelProvider utility method

test/model-provider.test.ts

@@ -0,0 +1,31 @@
+import { getModelProvider } from "../app/utils/model";
+
+describe("getModelProvider", () => {
+  test("should return model and provider when input contains '@'", () => {
+    const input = "model@provider";
+    const [model, provider] = getModelProvider(input);
+    expect(model).toBe("model");
+    expect(provider).toBe("provider");
+  });
+
+  test("should return model and undefined provider when input does not contain '@'", () => {
+    const input = "model";
+    const [model, provider] = getModelProvider(input);
+    expect(model).toBe("model");
+    expect(provider).toBeUndefined();
+  });
+
+  test("should handle multiple '@' characters correctly", () => {
+    const input = "model@provider@extra";
+    const [model, provider] = getModelProvider(input);
+    expect(model).toBe("model@provider");
+    expect(provider).toBe("extra");
+  });
+
+  test("should return empty strings when input is empty", () => {
+    const input = "";
+    const [model, provider] = getModelProvider(input);
+    expect(model).toBe("");
+    expect(provider).toBeUndefined();
+  });
+});