fix: align JS with PHP data structure and NAVODILA.txt

Critical fixes:
- JS now correctly reads PHP data structure:
  - employees.byId (object) instead of employees (array)
  - aggregatedEvents array with employee_id, period, *_minutes
  - vacationQuota.byEmployee with available, planned, used, entitlement
  - orgUnits array with id, name, employees, employeeCount

- TIME conversion: All values from SPICA are in MINUTES
  - Added /60 conversion to get hours
  - Added /60/8 to get days

- Formulas from Podatkovni model.dc.html:
  - Planirane ure = HC × delovni dnevi × 8
  - Stopnja bolniške = bolniške ure / planirane ure × 100
  - Neto kapaciteta = 1 − (bolniške + dopust) / planirane ure

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
