feat(tickets): suppression d'un ticket (backend + frontend)

Ajoute la suppression complète d'un ticket (#6).

Backend Rust :
- port IssueStore::delete (NotFound si absent) + event IssueDeleted{freed_sprint}
- FsIssueStore::delete : supprime .ideai/tickets/<N>/ et l'index sous lock
- use case DeleteIssue + adaptations des tests sprint/ticket_assistant au port
- commande Tauri ticket_delete + câblage events/state/lib

Frontend :
- gateway delete (ports, adapter ticket + mock, domain)
- useTicketDetail : retrait de la liste et fermeture du détail via event issueDeleted
- intégration TicketDetail + tests

Tests verts : application/issue_usecases (6), infrastructure/issue_store (7),
app-tauri --lib (56), frontend vitest (503), npm run build (exit 0).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/app-tauri/src/tickets.rs

@@ -15,10 +15,10 @@ use uuid::Uuid;
 
 use application::{
     AppError, AssignIssueAgentInput, AssignTicketToSprintInput, CloseTicketAssistantInput,
-    CreateIssueInput, CreateSprintInput, DeleteSprintInput, LinkIssuesInput, ListIssuesInput,
-    ListSprintsInput, OpenProjectInput, OpenTicketAssistantInput, ReadIssueCarnetInput,
-    ReadIssueInput, RenameSprintInput, ReorderSprintsInput, UnassignTicketFromSprintInput,
-    UnlinkIssuesInput, UpdateIssueCarnetInput, UpdateIssueInput,
+    CreateIssueInput, CreateSprintInput, DeleteIssueInput, DeleteSprintInput, LinkIssuesInput,
+    ListIssuesInput, ListSprintsInput, OpenProjectInput, OpenTicketAssistantInput,
+    ReadIssueCarnetInput, ReadIssueInput, RenameSprintInput, ReorderSprintsInput,
+    UnassignTicketFromSprintInput, UnlinkIssuesInput, UpdateIssueCarnetInput, UpdateIssueInput,
 };
 use domain::{
     AgentId, AgentIssueRole, Issue, IssueActor, IssueCarnet, IssueIndexEntry, IssueLink,
@@ -180,6 +180,15 @@ pub struct TicketReadRequestDto {
     pub include_carnet: Option<bool>,
 }
 
+/// Delete request.
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TicketDeleteRequestDto {
+    #[serde(default)]
+    pub project_id: String,
+    pub r#ref: String,
+}
+
 /// List request.
 #[derive(Debug, Clone, Deserialize)]
 #[serde(rename_all = "camelCase")]
@@ -612,6 +621,23 @@ pub async fn ticket_read(
     Ok(TicketDto::from_issue(issue, carnet))
 }
 
+#[tauri::command]
+pub async fn ticket_delete(
+    request: TicketDeleteRequestDto,
+    state: State<'_, AppState>,
+) -> Result<(), ErrorDto> {
+    let project = resolve_project(&state, &request.project_id).await?;
+    state
+        .delete_issue
+        .execute(DeleteIssueInput {
+            project,
+            issue_ref: parse_ref_dto(&request.r#ref)?,
+        })
+        .await
+        .map(|_| ())
+        .map_err(ErrorDto::from)
+}
+
 #[tauri::command]
 pub async fn open_ticket_chat(
     request: OpenTicketChatRequestDto,