bulk operations fixes

- Frontend: implémente bulkDelete, bulkArchive, bulkRestore
- Backend: adapts ticket DTOs pour bulk operations
- Infrastructure: MCP server pour gestion bulk tickets
- Tests: coverage frontend + backend

crates/backend/src/openai_tools.rs

@@ -357,7 +357,9 @@ fn is_ticket_policy_mutation_tool(name: &str) -> bool {
 fn is_ticket_policy_bulk_mutation_tool(name: &str) -> bool {
     matches!(
         name,
-        "idea_ticket_bulk_update_status" | "idea_ticket_bulk_update_priority"
+        "idea_ticket_bulk_update_status"
+            | "idea_ticket_bulk_update_priority"
+            | "idea_ticket_bulk_delete"
     )
 }