Add OpenTelemetry observability with local JSONL traces (#347)

Co-authored-by: 0xallam <ahmed39652003@gmail.com>

tests/llm/test_llm_otel.py

@@ -0,0 +1,15 @@
+import litellm
+
+from strix.llm.config import LLMConfig
+from strix.llm.llm import LLM
+
+
+def test_llm_does_not_modify_litellm_callbacks(monkeypatch) -> None:
+    monkeypatch.setenv("STRIX_TELEMETRY", "1")
+    monkeypatch.setenv("STRIX_OTEL_TELEMETRY", "1")
+    monkeypatch.setattr(litellm, "callbacks", ["custom-callback"])
+
+    llm = LLM(LLMConfig(model_name="openai/gpt-5"), agent_name=None)
+
+    assert llm is not None
+    assert litellm.callbacks == ["custom-callback"]