Pin harness to 99fc607 (XML <cite> citation syntax)

Picks up:
- Switch from [file: "quote"] bracket syntax to <cite file="X">quote</cite>
XML tags. Fixes leaked chrome when the model added emphasis chars
around the citation.
- Tenacity dep for litellm retry path (avoids ModuleNotFoundError on
finish_reason='error' / MALFORMED_FUNCTION_CALL).
- Docker daemon auto-launch on macOS (dev only; no effect in the Space).
- Lower process_citations cyclomatic complexity.
- Extract HTML primitives into block_render module.

Co-Authored-By: Claude Opus 4.7 (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@48d2621
+a-simple-llm-harness @ git+https://github.com/chuckfinca/a-simple-llm-harness.git@99fc607
 e2b-code-interpreter>=2.5
 huggingface-hub
 python-dotenv