docs: migrer schémas BDD de Mermaid vers DBML

Remplace les diagrammes Mermaid par DBML (via kroki-dbml) pour
une meilleure expressivité des schémas de base de données :
- Ajout support notes, contraintes et indexes détaillés
- Migration de tous les schémas d'entités partagées
- Ajout fichier exemple dbml-example.md
- Configuration plugin mkdocs-kroki pour rendu DBML

docs/domains/_shared/entities/reports.md

@@ -4,26 +4,67 @@
 
 ## Diagramme
 
-```mermaid
-erDiagram
-    USERS ||--o{ REPORTS : "signale"
-    CONTENTS ||--o{ REPORTS : "reçoit"
-    USERS ||--o{ REPORTS : "modère"
+```kroki-dbml
+Table users {
+  id uuid [primary key]
+  username varchar(50)
+}
 
-    REPORTS {
-        uuid id PK
-        uuid content_id FK
-        uuid reporter_id FK
-        uuid moderator_id FK
-        string category
-        string status
-        text comment
-        string evidence_url
-        timestamp reported_at
-        timestamp reviewed_at
-        text moderator_notes
-        string action_taken
-    }
+Table contents {
+  id uuid [primary key]
+  title varchar(255)
+  user_id uuid [not null]
+}
+
+Table reports {
+  id uuid [primary key]
+  content_id uuid [not null, ref: > contents.id, note: 'Content being reported']
+  reporter_id uuid [not null, ref: > users.id, note: 'User who filed the report']
+  moderator_id uuid [ref: > users.id, note: 'Moderator assigned to review (NULL if pending)']
+  category report_category_enum [not null]
+  status report_status_enum [not null, default: 'pending']
+  comment text [note: 'Reporter explanation (mandatory for "other" category)']
+  evidence_url varchar(512) [note: 'Screenshot or additional proof URL']
+  reported_at timestamp [not null, default: `now()`]
+  reviewed_at timestamp [note: 'When moderator reviewed the report']
+  moderator_notes text [note: 'Internal moderator notes']
+  action_taken report_action_enum [note: 'Action decided by moderator']
+
+  indexes {
+    (content_id, status) [note: 'Find all reports for a content']
+    (status, reported_at) [note: 'Queue for moderators (pending first)']
+    (reporter_id) [note: 'User report history (detect abuse)']
+    (moderator_id) [note: 'Reports assigned to moderator']
+  }
+}
+
+Enum report_category_enum {
+  spam [note: 'Contenu publicitaire non sollicité']
+  hate_speech [note: 'Discours haineux, discrimination']
+  violence [note: 'Violence explicite']
+  sexual_content [note: 'Contenu sexuel inapproprié']
+  misinformation [note: 'Désinformation, fake news']
+  copyright [note: 'Violation de droits d auteur']
+  wrong_age_rating [note: 'Classification d âge incorrecte']
+  other [note: 'Autre raison (commentaire obligatoire)']
+}
+
+Enum report_status_enum {
+  pending [note: 'En attente de revue']
+  under_review [note: 'En cours d examen par modérateur']
+  actioned [note: 'Action prise (contenu retiré/édité)']
+  dismissed [note: 'Signalement rejeté (contenu valide)']
+  duplicate [note: 'Doublon d un signalement existant']
+}
+
+Enum report_action_enum {
+  content_removed [note: 'Contenu supprimé']
+  content_edited [note: 'Métadonnées modifiées (âge, tags)']
+  warning_sent [note: 'Avertissement au créateur']
+  strike_issued [note: 'Strike ajouté au créateur']
+  account_suspended [note: 'Compte créateur suspendu']
+  no_action [note: 'Aucune action (signalement infondé)']
+}
 ```
 
 ## Légende