test(desktop): cover the workspace-page reveal bug class

Both layers, and the classification underneath them: a page route fronts
the pane whether it carries a query or not, moving between two pages
fronts it again even though `$workspaceIsPage` never changes, contributed
routes count, and chat and overlay targets leave the tab alone.

apps/desktop/src/app/routes.workspace-reveal.test.ts

@@ -0,0 +1,189 @@
+/**
+ * A full page (Capabilities/Messaging/Artifacts/a contributed route) renders
+ * INSIDE the `workspace` pane, so navigating to one has to front that pane —
+ * otherwise a main zone parked on a session tile keeps the tile on screen and
+ * the click looks dead until the app restarts (#72602).
+ *
+ * Two layers, both covered here: `syncWorkspaceRoute` (the router location,
+ * every entry point) and `navigateToWorkspacePage` (the re-click, where the
+ * location doesn't change).
+ */
+
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { registry } from '@/contrib/registry'
+
+import {
+  $workspaceIsPage,
+  AGENTS_ROUTE,
+  appViewForPath,
+  ARTIFACTS_ROUTE,
+  CRON_ROUTE,
+  MESSAGING_ROUTE,
+  navigateToWorkspacePage,
+  NEW_CHAT_ROUTE,
+  routePathname,
+  ROUTES_AREA,
+  routeSessionId,
+  sessionRoute,
+  SETTINGS_ROUTE,
+  SKILLS_ROUTE,
+  syncWorkspaceRoute
+} from './routes'
+
+vi.mock('@/components/pane-shell/tree/store', async importOriginal => ({
+  ...(await importOriginal<Record<string, unknown>>()),
+  noteActiveTreeGroup: vi.fn(),
+  revealTreePane: vi.fn()
+}))
+
+const { noteActiveTreeGroup, revealTreePane } = await import('@/components/pane-shell/tree/store')
+
+const CONTRIBUTED_ROUTE = '/kanban'
+
+function contributeRoute(): () => void {
+  return registry.register({
+    area: ROUTES_AREA,
+    data: { path: CONTRIBUTED_ROUTE },
+    id: 'test-route',
+    render: () => null
+  })
+}
+
+/** Did the workspace pane get fronted? Both calls, or the tab stays put. */
+const fronted = () =>
+  vi.mocked(revealTreePane).mock.calls.some(([pane]) => pane === 'workspace') &&
+  vi.mocked(noteActiveTreeGroup).mock.calls.some(([group]) => group === null)
+
+beforeEach(() => {
+  vi.mocked(revealTreePane).mockClear()
+  vi.mocked(noteActiveTreeGroup).mockClear()
+  $workspaceIsPage.set(false)
+})
+
+afterEach(() => {
+  $workspaceIsPage.set(false)
+})
+
+describe('routePathname', () => {
+  it('keeps a bare path and drops a query or hash', () => {
+    expect(routePathname(SKILLS_ROUTE)).toBe('/skills')
+    expect(routePathname('/skills?tab=mcp')).toBe('/skills')
+    expect(routePathname('/skills?tab=mcp&server=ctx7')).toBe('/skills')
+    expect(routePathname('/settings#keys')).toBe('/settings')
+  })
+
+  it('leaves an encoded session id alone', () => {
+    const route = sessionRoute('a?b#c')
+
+    expect(routePathname(route)).toBe(route)
+    expect(routeSessionId(route)).toBe('a?b#c')
+  })
+})
+
+describe('classification of targets carrying a query', () => {
+  // The palette navigates to every one of these (Capabilities tabs, MCP
+  // servers), and Settings redirects old /settings?tab=mcp deep links to the
+  // last one. Unstripped, they parsed as SESSION ids and read as 'chat'.
+  it.each([
+    [`${SKILLS_ROUTE}?tab=skills`, 'skills'],
+    [`${SKILLS_ROUTE}?tab=toolsets`, 'skills'],
+    [`${SKILLS_ROUTE}?tab=mcp&server=ctx7`, 'skills'],
+    [`${SETTINGS_ROUTE}?tab=keys`, 'settings']
+  ])('%s is not a session route', (to, view) => {
+    expect(routeSessionId(to)).toBeNull()
+    expect(appViewForPath(to)).toBe(view)
+  })
+})
+
+describe('syncWorkspaceRoute', () => {
+  it('publishes and fronts on a page route', () => {
+    syncWorkspaceRoute(SKILLS_ROUTE)
+
+    expect($workspaceIsPage.get()).toBe(true)
+    expect(fronted()).toBe(true)
+  })
+
+  it('fronts on a page route reached with a query', () => {
+    syncWorkspaceRoute(`${SKILLS_ROUTE}?tab=mcp`)
+
+    expect($workspaceIsPage.get()).toBe(true)
+    expect(fronted()).toBe(true)
+  })
+
+  it('fronts when moving between two pages — the atom never changes, the tab must', () => {
+    syncWorkspaceRoute(ARTIFACTS_ROUTE)
+    vi.mocked(revealTreePane).mockClear()
+    vi.mocked(noteActiveTreeGroup).mockClear()
+
+    syncWorkspaceRoute(MESSAGING_ROUTE)
+
+    expect($workspaceIsPage.get()).toBe(true)
+    expect(fronted()).toBe(true)
+  })
+
+  it('fronts on a contributed page route', () => {
+    const dispose = contributeRoute()
+
+    try {
+      syncWorkspaceRoute(CONTRIBUTED_ROUTE)
+
+      expect(appViewForPath(CONTRIBUTED_ROUTE)).toBe('extension')
+      expect(fronted()).toBe(true)
+    } finally {
+      dispose()
+    }
+  })
+
+  it.each([
+    ['a session route', sessionRoute('sess-a')],
+    ['the new-chat route', NEW_CHAT_ROUTE],
+    ['an overlay', SETTINGS_ROUTE],
+    ['an overlay with a query', `${SETTINGS_ROUTE}?tab=keys`],
+    ['another overlay', CRON_ROUTE],
+    ['yet another overlay', AGENTS_ROUTE]
+  ])('leaves the tab alone on %s', (_label, to) => {
+    syncWorkspaceRoute(to)
+
+    expect($workspaceIsPage.get()).toBe(false)
+    expect(revealTreePane).not.toHaveBeenCalled()
+  })
+})
+
+describe('navigateToWorkspacePage', () => {
+  it('navigates and fronts, so a re-click on the page you are already on still shows it', () => {
+    const navigate = vi.fn()
+
+    navigateToWorkspacePage(navigate, SKILLS_ROUTE)
+
+    expect(navigate).toHaveBeenCalledWith(SKILLS_ROUTE, undefined)
+    expect(fronted()).toBe(true)
+  })
+
+  it.each([`${SKILLS_ROUTE}?tab=skills`, `${SKILLS_ROUTE}?tab=toolsets`, `${SKILLS_ROUTE}?tab=mcp&server=ctx7`])(
+    'fronts for the palette target %s',
+    to => {
+      navigateToWorkspacePage(vi.fn(), to)
+
+      expect(fronted()).toBe(true)
+    }
+  )
+
+  it('passes navigation options through', () => {
+    const navigate = vi.fn()
+
+    navigateToWorkspacePage(navigate, ARTIFACTS_ROUTE, { replace: true })
+
+    expect(navigate).toHaveBeenCalledWith(ARTIFACTS_ROUTE, { replace: true })
+  })
+
+  it('navigates without fronting for chat and overlay targets', () => {
+    const navigate = vi.fn()
+
+    navigateToWorkspacePage(navigate, sessionRoute('sess-a'))
+    navigateToWorkspacePage(navigate, SETTINGS_ROUTE)
+
+    expect(navigate).toHaveBeenCalledTimes(2)
+    expect(revealTreePane).not.toHaveBeenCalled()
+  })
+})