feat(workstate): UI live-state des conversations/délégations (Lot A frontend)

Ajoute le port et l'adaptateur workState (+ mock) côté frontend, le type domaine
associé, et la feature `workstate` (panneau ProjectWorkStatePanel + hook
useProjectWorkState) consommant le read-model live exposé par le backend.
Intègre le panneau dans ProjectsView. Tests verts (workstate + projects).

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

frontend/src/features/projects/ProjectsView.tsx

@@ -38,6 +38,7 @@ import { SkillsPanel } from "@/features/skills";
 import { MemoryPanel } from "@/features/memory";
 import { EmbedderSettings } from "@/features/embedder";
 import { PermissionsPanel } from "@/features/permissions";
+import { ProjectWorkStatePanel } from "@/features/workstate";
 import { GitPanel, GitGraphView } from "@/features/git";
 import { Button, Input, Panel, Tabs, cn } from "@/shared";
 import { useGateways } from "@/app/di";
@@ -47,6 +48,7 @@ import { useProjects } from "./useProjects";
 type SidebarTab =
   | "projects"
   | "context"
+  | "work"
   | "agents"
   | "templates"
   | "skills"
@@ -57,6 +59,7 @@ type SidebarTab =
 const SIDEBAR_TABS: { id: SidebarTab; label: string }[] = [
   { id: "projects", label: "Projects" },
   { id: "context", label: "Context" },
+  { id: "work", label: "Work" },
   { id: "agents", label: "Agents" },
   { id: "templates", label: "Templates" },
   { id: "skills", label: "Skills" },
@@ -282,6 +285,14 @@ export function ProjectsView() {
               <p className="text-sm text-muted">Open a project to edit context.</p>
             )}
 
+            {/* Work-state panel */}
+            {sidebarTab === "work" && active && (
+              <ProjectWorkStatePanel projectId={active.id} />
+            )}
+            {sidebarTab === "work" && !active && (
+              <p className="text-sm text-muted">Open a project to view work state.</p>
+            )}
+
             {/* Agents panel — only rendered when active project exists */}
             {sidebarTab === "agents" && active && (
               <AgentsPanel projectId={active.id} projectRoot={active.root} />