feat(tickets): tri de la liste de tickets côté backend (#21)

Ajoute le paramètre de tri dans TicketListQuery et l'expose via
ticket_list (surface app-tauri + MCP). Ports et adaptateur mock
frontend alignés sur le contrat de tri. La partie UI (contrôle de tri
dans TicketFacetsBar) suivra dans un commit frontend dédié.

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

frontend/src/adapters/mock/index.ts

@@ -46,6 +46,8 @@ import type {
   TicketLink,
   TicketLinkKind,
   TicketList,
+  TicketPriority,
+  TicketStatus,
   TurnPage,
   TurnView,
   Unsubscribe,
@@ -87,6 +89,44 @@ import type {
 import { normalizeProjectWorkState } from "../workStateNormalization";
 import { applyOperation, singleLeafTree } from "@/features/layout/layout";
 
+const TICKET_PRIORITY_RANK: Record<TicketPriority, number> = {
+  low: 0,
+  medium: 1,
+  high: 2,
+  critical: 3,
+};
+
+const TICKET_STATUS_RANK: Record<TicketStatus, number> = {
+  open: 0,
+  inProgress: 1,
+  QA: 2,
+  closed: 3,
+};
+
+function sortTickets(
+  rows: Ticket[],
+  sort: NonNullable<TicketListQuery["sort"]>,
+): Ticket[] {
+  return rows.sort((a, b) => {
+    let fieldOrder = 0;
+    if (sort.field === "number") {
+      fieldOrder = a.number - b.number;
+    } else if (sort.field === "priority") {
+      fieldOrder =
+        TICKET_PRIORITY_RANK[a.priority] - TICKET_PRIORITY_RANK[b.priority];
+    } else if (sort.field === "status") {
+      fieldOrder = TICKET_STATUS_RANK[a.status] - TICKET_STATUS_RANK[b.status];
+    } else {
+      fieldOrder =
+        a.title.localeCompare(b.title, undefined, { sensitivity: "base" }) ||
+        a.title.localeCompare(b.title);
+    }
+
+    const directed = sort.direction === "desc" ? -fieldOrder : fieldOrder;
+    return directed || a.number - b.number;
+  });
+}
+
 export class MockSystemGateway implements SystemGateway {
   private listeners = new Set<(e: DomainEvent) => void>();
 
@@ -1955,7 +1995,7 @@ export class MockTicketGateway implements TicketGateway {
     // empty/absent set means "no constraint" (all values pass).
     const statuses = q.statuses ?? [];
     const priorities = q.priorities ?? [];
-    const rows = [...this.projectTickets(projectId).values()]
+    let rows = [...this.projectTickets(projectId).values()]
       .filter((t) => statuses.length === 0 || statuses.includes(t.status))
       .filter((t) => priorities.length === 0 || priorities.includes(t.priority))
       .filter(
@@ -1967,8 +2007,10 @@ export class MockTicketGateway implements TicketGateway {
           !text ||
           t.title.toLowerCase().includes(text) ||
           t.description.toLowerCase().includes(text),
-      )
-      .sort((a, b) => b.number - a.number);
+      );
+    rows = q.sort
+      ? sortTickets(rows, q.sort)
+      : rows.sort((a, b) => b.number - a.number);
     const start = Number.parseInt(q.cursor ?? "0", 10) || 0;
     const limit = Math.min(Math.max(q.limit ?? 100, 1), 500);
     const end = Math.min(rows.length, start + limit);