feat(ts-sdk): add LiteLLM as LLM provider (#5830)

Co-authored-by: kartik-mem0 <kartik.labhshetwar@mem0.ai>

mem0-ts/src/oss/tests/factory.unit.test.ts

@@ -92,6 +92,11 @@ jest.mock("../src/llms/deepseek", () => ({
     .fn()
     .mockImplementation((config) => ({ type: "deepseek-llm", config })),
 }));
+jest.mock("../src/llms/litellm", () => ({
+  LiteLLM: jest
+    .fn()
+    .mockImplementation((config) => ({ type: "litellm-llm", config })),
+}));
 
 jest.mock("../src/vector_stores/qdrant", () => ({
   Qdrant: jest
@@ -206,6 +211,7 @@ describe("LLMFactory", () => {
     ["langchain"],
     ["lmstudio"],
     ["deepseek"],
+    ["litellm"],
   ])("creates LLM for provider '%s'", (provider) => {
     expect(() => LLMFactory.create(provider, dummyLLMConfig)).not.toThrow();
   });