10 testing validation

12) Validation & Quality Assurance

12.1 Accuracy Spot Checks

Test app with real users in:

• Cold climates: Alaska (1a–7b), Minnesota (3a–4b), Maine (3b–6a)
• Hot climates: Arizona (4b–10b), Florida (8a–11a), Hawaii (10a–13b)
• High altitude: Colorado (3a–7a), Montana (3a–6b)
• Diverse: California (5a–11a spans entire state)
• Mid-range: Virginia (5b–8a), Washington (5a–9a)

12.2 Data Quality Metrics

• Zone accuracy: 99%+ (PRISM is authoritative)
• Frost date accuracy: within ±7 days of NOAA normals
• Native plant accuracy: match state extension lists
• Invasive flags: match EDDMapS state reports

12.3 Automated Test Suite

Extend qa/scenarios/ with:

• qa/scenarios/50-state/state-inference-.json
• Test zone lookup for all states
• Test frost date API for diverse ZIPs
• Test native plant filtering per state