Function normalizeLongitude

normalizeLongitude(lon: number): number
Normalize longitude to valid range (-180 to +180)

Accepts both -180/+180 and 0/360 formats and normalizes to -180/+180.
Parameters
- lon: number
  Input longitude in degrees
Returns number
Normalized longitude in range (-180, +180]
Example
```
normalizeLongitude(45.5)      // 45.5 (already valid)
normalizeLongitude(185)       // -175 (wrapped)
normalizeLongitude(-185)      // 175 (wrapped)
normalizeLongitude(360)       // 0 (wrapped)
normalizeLongitude(720)       // 0 (multiple wraps)
```
- Defined in houses/validation.ts:63