feat(trajet, avenant): migrate from MUI to ShadCN/Tailwind grid design

Summary

• Migrate the trajet and avenant sections from MUI components to the ShadCN/Tailwind CSS Grid table design, aligning them with the already-migrated circuit and usager sections
• Unify the TableControlBar (Colonnes, Filtres, Rafraîchir, Exporter) styling across all sections using the shared ShadCN component with btn-primary-glow and glow-primary hover
  effects

Changes

Trajet (4 files)

• trajet-table.tsx — Rewrite with CSS Grid layout, synchronized horizontal scroll
  (header/body/scrollbar), loading skeletons, empty state
• trajet-table-row.tsx — Div-based grid row with IntersectionObserver entrance animations, neo-shadow hover effects, color accent bar, ShadCN Checkbox and TableActionColumn
• trajet-list-view.tsx — Switch to ShadCN TabsCustom, TabContentContainer, and ShadCN
  TableControlBar
• trajet-new-view.tsx — Migrate form to ShadCN FormContainer, TabbedForm, and FormField
  with card sections

Avenant (7 files)

• avenant-table.tsx (new) — CSS Grid table with scroll sync, horizontal scrollbar,
  loading skeletons, empty state, pagination
• avenant-table-row.tsx — Div-based grid row with entrance animations, neo-shadow hover, Tailwind status badges, full uncapped ID display
• avenant-list-view.tsx — Switch to ShadCN TabsCustom, TabContentContainer, and ShadCN
  TableControlBar
• avenant-new-view.tsx — Migrate form to ShadCN FormContainer, TabbedForm, and FormField
• avenant-details.tsx — Card sections layout (Etat & Dates, Informations, Affectation,
  Observations)
• avenant-horaire.tsx — Replace MUI Grid with Tailwind flex layout
• signature-field.tsx — Replace MUI Box/Typography/Button with Tailwind equivalents

Shared (1 file)

• table-control-bar.tsx — Unify ColumnSelector hover to always use glow-primary animation regardless of whether an add button exists