feat(tickets): filtres multi-critères par cases à cocher (backend + frontend)

Passe les filtres de la liste des tickets en sélection multiple (#12).

Backend Rust :
- IssueListFilter : statuses/priorities en Vec, filter_matches en OR intra-champ
  et AND inter-champs
- TicketListRequestDto en tableaux + from_request (parse/déduplication)
- MCP idea_ticket_list aligné sur le nouveau contrat

Frontend :
- TicketListQuery.statuses/priorities
- UI de cases à cocher, toggle/clear des filtres

Tests verts : issue_store (7), app-tauri --lib (59), mcp_server (24),
issue_usecases (6), sprint_usecases (6), frontend vitest (505), npm run build (exit 0).

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

crates/infrastructure/src/issues.rs

@@ -231,13 +231,10 @@ async fn write_index(root: &ProjectPath, rows: &[IssueIndexEntry]) -> Result<(),
 }
 
 fn filter_matches(row: &IssueIndexEntry, filter: &IssueListFilter) -> bool {
-    if filter.status.is_some_and(|status| row.status != status) {
+    if !filter.statuses.is_empty() && !filter.statuses.contains(&row.status) {
         return false;
     }
-    if filter
-        .priority
-        .is_some_and(|priority| row.priority != priority)
-    {
+    if !filter.priorities.is_empty() && !filter.priorities.contains(&row.priority) {
         return false;
     }
     if let Some(agent_id) = filter.assigned_agent_id {