feat(portfolio): market cycle indicators — price, DOM, supply, rent growth

[paruff]

Problem

Pros track market cycle indicators daily: median price, days on market, months of supply, price-to-income ratio, rent growth trends. prei has none of these.

Acceptance Criteria

• Create MarketIndicator model: metro_area, indicator_type, value, date_recorded
• Indicator types: median_price, dom, months_supply, price_to_income, rent_growth_yoy
• Create core/integrations/market/market_trends.py adapter (Zillow Research data, Census, BLS)
• Add market health dashboard view at /markets/
• Show trend charts (sparkline or simple bar) for each indicator per market
• Color-code: green (healthy), yellow (caution), red (overheated/declining)
• Add link from growth area detail to market indicators
• Management command: python manage.py update_market_indicators
• E2E test: market dashboard renders with indicators for tracked markets
• Unit tests for indicator classification logic

Implementation Guide (for opencode/mimo v2.5)

1. Create MarketIndicator model in core/models/growth.py
2. Create core/integrations/market/market_trends.py adapter
3. Create core/management/commands/update_market_indicators.py
4. Add market_dashboard view to core/views/__init__.py
5. Create templates/markets/dashboard.html
6. Add URL pattern markets/
7. Migration for new model

Dependencies

• Requires: Zillow Research API or Census/BLS data access
• Enhances: Growth area scoring (market cycle as additional input)

[paruff]

Duplicate of #383 which was merged in PR #383