Pin harness to 48d2621 (bare citation fallback)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

requirements.txt

@@ -1,6 +1,6 @@
 click>=8.1
 litellm @ git+https://github.com/BerriAI/litellm.git@d251238
-a-simple-llm-harness @ git+https://github.com/chuckfinca/a-simple-llm-harness.git@8821d87
+a-simple-llm-harness @ git+https://github.com/chuckfinca/a-simple-llm-harness.git@48d2621
 e2b-code-interpreter>=2.5
 huggingface-hub
 python-dotenv