VSN-2585 — Migrate fiches & modals to shadcn (flottes + RH)

Summary

Flottes

• Fiche Carte Carburant (/dashboard/flottes/consommation/fuelcard): Migrated from MUI to shadcn — purple section card with CreditCard icon, shadcn FormField/FormContainer/ActionButtons, sonner toasts. Removed TabbedForm wrapper (single tab → direct render).
• Fiche Révision (/dashboard/flottes/revision): Fixed action buttons (Annuler/Enregistrer) showing in view mode — replaced MUI FormActions with shadcn ActionButtons wrapped in ConditionalComponent.
• Fiche Réparation (/dashboard/flottes/entretien/reparation): Same fix — action buttons hidden in view mode.

RH

• Modal "Envoyer un Formulaire" (/dashboard/rh/recrutement/candidatures): Migrated from MUI StyledDialog/StyledSelect/StyledTextField to shadcn Dialog/Select/Textarea with purple header and Send icon.
• Modal "Envoi d'un mail" (/dashboard/rh/recrutement/candidatures): Migrated from MUI to shadcn Dialog/Input/Textarea with purple header and Mail icon.
• Modal "Générer contrat" (/dashboard/rh/salarie): Migrated from MUI Dialog/Typography/Stack/AddButton to shadcn Dialog/Button with purple header and FileText/Download/Send Lucide icons.

Files modified (7)

• src/shared/sections/fleets/consommation/fuelcard/components/fuel-card-tab.tsx
• src/shared/sections/fleets/consommation/fuelcard/view/fuel-card-new-view.tsx
• src/shared/sections/fleets/revision/components/revision-form.tsx
• src/shared/sections/fleets/reparation/components/vehicle-repair-tab.tsx
• src/shared/sections/rh/recrutement/candidatures/components/send-form-modal.tsx
• src/shared/sections/rh/recrutement/candidatures/components/send-email-modal.tsx
• src/shared/sections/rh/salarie/components/salarie-generation-dialog.tsx

Closes VSN-2585