Function eclipticToZodiac

eclipticToZodiac(longitude: number): ZodiacPosition
Convert ecliptic longitude to zodiac position

Takes a geocentric ecliptic longitude (0-360°) and determines which tropical zodiac sign it falls in, along with the precise degree, minute, and second within that sign.

Algorithm (based on Swiss Ephemeris):
1. Normalize longitude to 0-360° range
2. Calculate sign index: floor(longitude / 30)
3. Calculate degree within sign: longitude % 30
4. Convert decimal degrees to degrees/minutes/seconds
5. Handle rounding edge cases
Parameters
- longitude: number
  Ecliptic longitude in degrees (0-360, but accepts any value)
Returns ZodiacPosition
Complete zodiac position with sign, degree, and formatting
Example
```
// Simple example
const pos = eclipticToZodiac(15.5);
// pos.sign = Sign.Aries
// pos.degree = 15, pos.minute = 30, pos.second = 0
// pos.formatted = "15°30'00\" Aries"
```
Example
```
// Meeus Example 25.a: Venus on 1992 Oct 13
const venus = eclipticToZodiac(217.411111);
// venus.sign = Sign.Scorpio
// venus.degree = 7, venus.minute = 24, venus.second = 40
// venus.formatted = "7°24'40\" Scorpio"
```
Example
```
// Handles normalization
eclipticToZodiac(360);  // 0° Aries (wraps around)
eclipticToZodiac(-1);   // 29° Pisces (negative wraps backward)
```
- Defined in zodiac/zodiac.ts:99