Addresses gemini-code-assist review feedback:
- All five files (portfolio_manager, research_manager, bear/bull researchers,
trader) now call .strip() on past_memory_str before injecting it into prompts,
removing the trailing '\n\n' artifacts from the construction loop.
- portfolio_manager now also makes the 'past reflections' phrasing in the
Investment Thesis instruction conditional on past_memories being non-empty,
so an empty memory section can't trigger hallucinated past reflections.
25cc0e144c