Fix #88: inject timestep macro summaries into next-turn prompts

[RandomOscillations]

Summary

• pass previous timestep summary into macro rendering so trend/momentum can be computed
• strengthen macro summary text for leader/minority framing, sentiment trend, exposure saturation, and action momentum
• render macro context under an explicit The Broader Climate heading in pass-1 prompts
• add targeted tests for macro rendering outputs and prompt inclusion

Testing

• pytest -q tests/test_engine.py::TestTokenAccumulation::test_macro_summary_renders_trend_and_saturation tests/test_engine.py::TestTokenAccumulation::test_macro_summary_renders_waiting_momentum tests/test_reasoning_prompts.py::TestPhaseAPromptFeatures::test_macro_summary_included
• ruff check extropy/simulation/engine.py extropy/simulation/reasoning.py tests/test_engine.py tests/test_reasoning_prompts.py

Closes #88

[DeveshParagiri]

Code Review

Verdict: ✅ Ready to merge

Summary

Implements macro state feedback per architecture doc §Fix 4 and Tenets 11-12. Previous timestep summary is now rendered into prompts under "## The Broader Climate".

Features Implemented

Feature	Rendering
Position distribution	Leader with majority/minority framing
Minority framing	"A sizable minority..." when runner-up ≥20% and leader ≥45%
Sentiment trend	Compares vs previous with ±0.08 threshold
Exposure saturation	Tiered: 95%+ "Almost everyone", 75%+ "Most people"
Action momentum	"More people taking action" when shares increased
Waiting momentum	"Still watching and waiting" when stalled

Edge Cases Handled

Case	Behavior
First timestep	prev_summary=None, trends default to 0 delta
Equal positions	Falls through to "People are still quite divided"
No position data	Skips position block
No sentiment data	Skips sentiment block

No changes required.