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/gin.settings.yml

@@ -0,0 +1,26 @@
+_core:
+  default_config_hash: c8aZhkIY8zHUo0_UOll4vVs_l48dHL_gBqbvfuAM0Rs
+favicon:
+  use_default: true
+features:
+  comment_user_picture: true
+  comment_user_verification: true
+  favicon: true
+  node_user_picture: true
+logo:
+  use_default: true
+third_party_settings:
+  shortcut:
+    module_link: true
+preset_accent_color: blue
+preset_focus_color: gin
+enable_darkmode: '1'
+classic_toolbar: new
+secondary_toolbar_frontend: true
+high_contrast_mode: false
+accent_color: ''
+focus_color: ''
+layout_density: default
+show_description_toggle: false
+show_user_theme_settings: false
+sticky_action_buttons: false