feat(backend): enhance departments, lots and agencies management (!197) · Requêtes de fusion · adanev / vsn / vsn-admin-service · GitLab

nabil.drissi a demandé de fusionner fearture/VSN-2508 vers develop mar. 31, 2026

Auto-format department name with predefined pattern (code + name)
Pre-fill lot number with LOT prefix (editable)
Add société flag for agencies with required legal info when enabled
Generate lot label (intitulé) from department + lot number (editable & unique)
Rename Infrastructure to Structure
Link subcontractors with contracts when agency is marked as société

Closes VSN-2508