feat: add 14 new overenskomst presets (GLS-A Gartneri/Skovbrug + KA/Krifa)

New GLS-A / 3F presets:
- Gartneri Standard/Elev u18/Elev o18 (50%/100% OT, Saturday split 12:30)
- Skovbrug Standard/Elev u18/Elev o18 (30%/100% OT)

New KA / Krifa presets:
- Landbrug Svine/Kvaeg Standard/Elev (50%/100% OT, 06:00-19:00)
- Landbrug Plantebrug Standard/Elev (50%/100% OT, 3h first tier)
- Landbrug Maskinstation Standard/Elev (30%/80% OT)
- Gron Standard/Elev (50%/100% OT, 3h first tier)

Plus E2E tests for KA/Krifa and Gartneri preset creation.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: renemadsen