fix: add starlette/httpx to dev deps, guard test_openai_compat imports

- Add starlette>=0.36 and httpx>=0.27 to dev dependencies so
  test_openai_compat.py can run in dev environments
- Add pytest.importorskip guards for starlette and fastapi so the
  test file is skipped gracefully when those packages are missing
- Fix import sorting (ruff I001)

340 tests now pass (was 325 with test_openai_compat skipped).

Co-Authored-By: Nakamoto, S <defi@defi-oracle.io>

pyproject.toml

@@ -35,6 +35,8 @@ dev = [
     "pytest>=7.4",
     "mypy>=1.8",
     "ruff>=0.4",
+    "starlette>=0.36",
+    "httpx>=0.27",
 ]
 all = ["fusionagi[openai,anthropic,local,gpu]"]