Initial Drupal site: content model + validation + Vue dashboard

- Content type "Ligne comptable" with Paragraphs "Répartition" (Compte + Montant)
- Taxonomies: Compte (9 comptes) and Client (unified client list)
- hook_node_presave + form validate: sum(répartition) must equal montant HT
- /dashboard route (progressive decoupling): Vue 3 app fetching JSON:API,
  computing solde par compte / par client client-side
- "Ajouter une ligne" opens the real Drupal node form in an AJAX modal
- Gin as default + admin theme
- 9 opening-balance lines seeded from suivi_compta_SASFigli2026_v2.ods

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

config/sync/field.storage.node.field_client.yml

@@ -0,0 +1,20 @@
+uuid: f89b3c64-5904-484f-8b25-1918680940b3
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+    - taxonomy
+id: node.field_client
+field_name: field_client
+entity_type: node
+type: entity_reference
+settings:
+  target_type: taxonomy_term
+module: core
+locked: false
+cardinality: 1
+translatable: true
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false