feat: password reset (endpoints forgot/reset, email service, migration colonnes)

feat: extraction CV multi-colonnes (detection de colonnes)

reintegration cascade delete-orphan

Batch-2: CosineScorer, delete/put candidats, BOM extraction, ranking, cascade delete, _can_access_profile, foreign_keys

Fix: preciser foreign_keys sur relation User.candidate (2 FK vers users)

Batch ameliorations: fix candidats, NER nom, recruiter_id + migration

Deploiement backend dans HF Spaces