PAP-88: remove Conference room + Artifacts nav items, routes & pages (D3)

Drop the two placeholder nav items from both classic and streamlined nav
(independent of the experimental flag per PAP-80 decision D3):
- Sidebar.tsx: remove the two SidebarNavItems + now-dead MessagesSquare/Package imports
- App.tsx: remove their routes and page imports
- company-routes.ts: drop conference-room/artifacts from BOARD_ROUTE_ROOTS
- delete placeholder pages ConferenceRoom.tsx and Artifacts.tsx
- company-routes.test.ts: remove the now-obsolete assertions

Grep clean; pnpm typecheck (ui) passes; company-routes unit test passes.

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

ui/src/App.tsx

@@ -10,8 +10,6 @@ import { Companies } from "./pages/Companies";
 import { Agents } from "./pages/Agents";
 import { AgentDetail } from "./pages/AgentDetail";
 import { Projects } from "./pages/Projects";
-import { ConferenceRoom } from "./pages/ConferenceRoom";
-import { Artifacts } from "./pages/Artifacts";
 import { ProjectDetail } from "./pages/ProjectDetail";
 import { ProjectWorkspaceDetail } from "./pages/ProjectWorkspaceDetail";
 import { Workspaces } from "./pages/Workspaces";
@@ -69,8 +67,6 @@ function boardRoutes() {
   return (
     <>
       <Route index element={<Navigate to="dashboard" replace />} />
-      <Route path="conference-room" element={<ConferenceRoom />} />
-      <Route path="artifacts" element={<Artifacts />} />
       <Route path="dashboard" element={<Dashboard />} />
       <Route path="dashboard/live" element={<DashboardLive />} />
       <Route path="onboarding" element={<OnboardingRoutePage />} />

ui/src/components/Sidebar.tsx

@@ -12,8 +12,6 @@ import {
   Repeat,
   GitBranch,
   Settings,
-  MessagesSquare,
-  Package,
   FolderOpen,
 } from "lucide-react";
 import { useQuery } from "@tanstack/react-query";
@@ -75,7 +73,6 @@ export function Sidebar() {
 
       <nav className="flex-1 min-h-0 overflow-y-auto scrollbar-auto-hide flex flex-col gap-4 pointer-coarse:gap-3 px-3 py-2">
         <div className="flex flex-col gap-0.5">
-          <SidebarNavItem to="/conference-room" label="Conference room" icon={MessagesSquare} />
           {/* New Task button aligned with nav items */}
           <button
             onClick={() => openNewIssue()}
@@ -103,7 +100,6 @@ export function Sidebar() {
           {showWorkspacesLink ? (
             <SidebarNavItem to="/workspaces" label="Workspaces" icon={GitBranch} />
           ) : null}
-          <SidebarNavItem to="/artifacts" label="Artifacts" icon={Package} />
           <SidebarNavItem to="/projects" label="Projects" icon={FolderOpen} />
           <PluginSlotOutlet
             slotTypes={["sidebar"]}

ui/src/lib/company-routes.test.ts

@@ -64,15 +64,4 @@ describe("company routes", () => {
       "/teams-catalog/core-exec-team",
     );
   });
-
-  it("treats /conference-room and /artifacts as board routes that need a company prefix", () => {
-    expect(isBoardPathWithoutPrefix("/conference-room")).toBe(true);
-    expect(isBoardPathWithoutPrefix("/artifacts")).toBe(true);
-    expect(extractCompanyPrefixFromPath("/conference-room")).toBeNull();
-    expect(extractCompanyPrefixFromPath("/artifacts")).toBeNull();
-    expect(applyCompanyPrefix("/conference-room", "PAP")).toBe("/PAP/conference-room");
-    expect(applyCompanyPrefix("/artifacts", "PAP")).toBe("/PAP/artifacts");
-    expect(toCompanyRelativePath("/PAP/conference-room")).toBe("/conference-room");
-    expect(toCompanyRelativePath("/PAP/artifacts")).toBe("/artifacts");
-  });
 });

ui/src/lib/company-routes.ts

@@ -20,8 +20,6 @@ const BOARD_ROUTE_ROOTS = new Set([
   "u",
   "design-guide",
   "search",
-  "conference-room",
-  "artifacts",
 ]);
 
 const GLOBAL_ROUTE_ROOTS = new Set(["auth", "invite", "board-claim", "cli-auth", "docs", "instance"]);

ui/src/pages/Artifacts.tsx

@@ -1,19 +0,0 @@
-import { useEffect } from "react";
-import { Package } from "lucide-react";
-import { EmptyState } from "../components/EmptyState";
-import { useBreadcrumbs } from "../context/BreadcrumbContext";
-
-export function Artifacts() {
-  const { setBreadcrumbs } = useBreadcrumbs();
-
-  useEffect(() => {
-    setBreadcrumbs([{ label: "Artifacts" }]);
-  }, [setBreadcrumbs]);
-
-  return (
-    <EmptyState
-      icon={Package}
-      message="Artifacts are coming soon."
-    />
-  );
-}

ui/src/pages/ConferenceRoom.tsx

@@ -1,19 +0,0 @@
-import { useEffect } from "react";
-import { MessagesSquare } from "lucide-react";
-import { EmptyState } from "../components/EmptyState";
-import { useBreadcrumbs } from "../context/BreadcrumbContext";
-
-export function ConferenceRoom() {
-  const { setBreadcrumbs } = useBreadcrumbs();
-
-  useEffect(() => {
-    setBreadcrumbs([{ label: "Conference room" }]);
-  }, [setBreadcrumbs]);
-
-  return (
-    <EmptyState
-      icon={MessagesSquare}
-      message="The conference room is coming soon."
-    />
-  );
-}