feat(agent): reprise des sessions au redémarrage (B2) — commande + ResumeProjectPanel

- Tauri : commande list_resumable_agents (projectId) + ResumableAgentListDto
  { resumable } / ResumableAgentDto (camelCase, conversationId omis si None),
  câblage state.rs (réutilise stores + ProfileStore, aucun nouveau port).
- Front : gateway listResumableAgents, ResumeProjectPanel monté à l'ouverture
  de projet (opt-in, FR) : Reprendre (launch_agent nodeId+conversationId),
  Nouvelle conversation (setCellConversation(null) puis launch), Ignorer,
  Tout reprendre/ignorer. resumeSupported=false ⇒ « relance à neuf ».
- doc : §15.2 coquille agents→resumable (alignée use case/back/front).

Tests : app-tauri dto 9/9 ; vitest 324 (+10) ; workspace Rust 0 échec. 0 régression.

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

frontend/src/features/projects/ProjectsView.tsx

@@ -32,7 +32,7 @@ import { useState } from "react";
 
 import type { LayoutInfo } from "@/domain";
 import { LayoutGrid, LayoutTabs } from "@/features/layout";
-import { AgentsPanel } from "@/features/agents";
+import { AgentsPanel, ResumeProjectPanel } from "@/features/agents";
 import { TemplatesPanel } from "@/features/templates";
 import { SkillsPanel } from "@/features/skills";
 import { MemoryPanel } from "@/features/memory";
@@ -339,6 +339,17 @@ export function ProjectsView() {
           )}
         </main>
       </div>
+
+      {/* ── Reopen resume panel (§15.2) ──
+          Mounted per active project (keyed by id) so it re-pulls the resumable
+          inventory on every open/switch; it renders nothing when empty. */}
+      {active && (
+        <ResumeProjectPanel
+          key={`resume-${active.id}`}
+          projectId={active.id}
+          cwd={active.root}
+        />
+      )}
     </div>
   );
 }