Summary

Adds a standalone financial sustainability calculator that derives financial health from raw revenue/expense data.

Changes

• New module services/analytics/financial_sustainability.py:
  • Break-even month detection
  • Revenue sustainability index (linear regression trend, 0-100)
  • Cost efficiency ratio with 5-tier assessment
  • Cash flow projection with runway calculation
  • Sustainability status classification (draft/grant_dependent/transitioning/self_sustaining/needs_rework)
• CLI: python3 -m services.analytics.financial_sustainability compute --location-id UUID

Tests

31 unit tests covering all calculator functions.