Merge origin/main into feat/wait-banner: resolve use-host-feeds import overlap

Conflict: src/client/sidebar/use-host-feeds.ts
- ours: import { mirrorAgentWaits, ... } from '../state.ts'
- theirs: same line + new import { isNarrowWidth } from '../breakpoints.ts'
Resolution keeps both imports; the two sides' semantic changes are in
disjoint regions (ours: tab-disabled wait mirroring; theirs:
activateTasksPage native-landing) and both survive intact.

tests/sidebar-auto-activation.spec.tsx

@@ -1,13 +1,21 @@
 /**
- * Real-Sidebar regressions for issue #162: background activity (a new
- * subagent, a new background job) activates the Tasks page in the bottom
- * workbench. The right column belongs to DSH's native Sidebar, so there is no
- * full-screen drawer to guard against any more — the activation lands in the
- * docked workbench on every viewport width.
+ * Auto-activation regressions for issue #162: background activity (a new
+ * subagent, a new background job) activates the Tasks page in DSH's NATIVE
+ * right Sidebar — the column the two auto-open switches and the README promise
+ * ("wide viewports also expand the sidebar, while narrow full-screen drawers
+ * are not forced open"). The plugin's own bottom workbench is NOT that
+ * surface: it serves only its own flows (its + menu, the first-expansion
+ * auto-terminal), so a background activation must leave it exactly as it was.
+ *
+ * The narrow half of that promise is a PARK: the host draws the native column
+ * fullscreen below 768px and expands it on every open, so the activation places
+ * the tab and puts the column back to collapsed (src/client/sidebar/
+ * use-host-feeds.ts `activateTasksPage`). The topology jump-back is an explicit
+ * user gesture and always takes the host's expansion.
  */
 // @vitest-environment jsdom
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
-import { createElement } from 'react'
+import { createElement, useEffect, useRef, type ReactNode } from 'react'
 import { createRoot, type Root } from 'react-dom/client'
 import { act } from 'react-dom/test-utils'
 
@@ -15,8 +23,13 @@ import { setupReactAct } from './test-utils.ts'
 setupReactAct()
 
 import { Sidebar } from '../src/client/Sidebar.tsx'
-import { allLeaves, createSidebarStore, firstLeaf, type SidebarStore } from '../src/client/state.ts'
-import { createBetterSidebarService, type BetterSidebarService } from '../src/client/service.ts'
+import { allLeaves, createSidebarStore, type SidebarStore } from '../src/client/state.ts'
+import {
+  createBetterSidebarService,
+  type BetterSidebarService,
+  type SidebarSurface,
+  type TabComponentProps,
+} from '../src/client/service.ts'
 import type { Context, SidebarSessionList } from '../src/context-types.ts'
 
 class FakeWebSocket {
@@ -45,10 +58,79 @@ function makeSessionFeed(initial: SidebarSessionList) {
 
 type SessionFeed = ReturnType<typeof makeSessionFeed>
 
+/** One recorded native-surface open. */
+interface NativeOpen {
+  sessionId: string
+  kind: string
+  params: unknown
+  revealIfOpened: boolean
+}
+
+/** The native right Sidebar, replaced by a recording stand-in: the shell's
+ *  opens must reach THIS surface, not the plugin's own layout. */
+interface NativeSurfaceSpy {
+  surface: SidebarSurface
+  opens: NativeOpen[]
+}
+
+function makeNativeSurfaceSpy(): NativeSurfaceSpy {
+  const opens: NativeOpen[] = []
+  return {
+    opens,
+    surface: {
+      openTab: input => { opens.push({ ...input }) },
+      openResource: () => {},
+      fileAddress: (sessionId, cwd, path) => `addr://${sessionId}${cwd ?? ''}${path}`,
+      close: () => undefined,
+      update: () => false,
+      activate: () => false,
+      has: () => false,
+    },
+  }
+}
+
+/** `ctx.sidebarRight`, replaced by a stand-in column: `isExpanded` reports the
+ *  current state, `toggleExpanded` flips it and counts the calls. */
+interface NativeColumnSpy {
+  face: { isExpanded: () => boolean; toggleExpanded: () => void }
+  toggles: number
+}
+
+function makeNativeColumnSpy(expanded: boolean): NativeColumnSpy {
+  const spy = {
+    toggles: 0,
+    expanded,
+    face: {} as { isExpanded: () => boolean; toggleExpanded: () => void },
+  }
+  spy.face = {
+    isExpanded: () => spy.expanded,
+    toggleExpanded: () => {
+      spy.toggles += 1
+      spy.expanded = !spy.expanded
+    },
+  }
+  return spy
+}
+
+/** Stands in for the Tasks page: its node click is the jump gesture that arms
+ *  the shell's jump-back (fired once, like a real click). */
+function JumpHarness({ onSubagentJump }: TabComponentProps): ReactNode {
+  const fired = useRef(false)
+  useEffect(() => {
+    if (fired.current) return
+    fired.current = true
+    onSubagentJump?.('child')
+  }, [onSubagentJump])
+  return null
+}
+
 interface MountedSidebar {
   store: SidebarStore
   service: BetterSidebarService
   feed: SessionFeed
+  surface: NativeSurfaceSpy
+  column: NativeColumnSpy
+  sessionId: string
   unmount: () => void
 }
 
@@ -59,7 +141,11 @@ function setViewport(width: number): void {
   Object.defineProperty(window, 'innerWidth', { configurable: true, value: width })
 }
 
-function mountSidebar(width: number, bottomOpen = false): MountedSidebar {
+function mountSidebar(
+  width: number,
+  bottomOpen = false,
+  options: { columnExpanded?: boolean } = {},
+): MountedSidebar {
   setViewport(width)
   vi.stubGlobal('WebSocket', FakeWebSocket)
   const sessionId = `auto-activation-${++sessionSeq}`
@@ -76,13 +162,18 @@ function mountSidebar(width: number, bottomOpen = false): MountedSidebar {
   store.setSession(sessionId)
   store.reduce(state => ({ ...state, bottomOpen }))
   const service = createBetterSidebarService(store)
-  service.registerTab({ id: 'subagent', title: 'Subagent', component: () => null })
+  const surface = makeNativeSurfaceSpy()
+  service.setSurface(surface.surface)
+  service.registerTab({ id: 'subagent', title: 'Subagent', component: JumpHarness })
+  const column = makeNativeColumnSpy(options.columnExpanded ?? false)
   const localeSnapshot = { active: 'en' }
   const ctx = {
     locale: { subscribe: () => () => {}, getSnapshot: () => localeSnapshot },
     sessions: { list: feed },
     betterSidebar: service,
-    get: (name: string) => name === 'betterSidebar' ? service : undefined,
+    get: (name: string) => name === 'betterSidebar'
+      ? service
+      : name === 'sidebarRight' ? column.face : undefined,
   } as unknown as Context
   const container = document.createElement('div')
   document.body.append(container)
@@ -92,6 +183,9 @@ function mountSidebar(width: number, bottomOpen = false): MountedSidebar {
     store,
     service,
     feed,
+    surface,
+    column,
+    sessionId,
     unmount: () => {
       act(() => { root.unmount() })
       container.remove()
@@ -101,6 +195,18 @@ function mountSidebar(width: number, bottomOpen = false): MountedSidebar {
   return result
 }
 
+type ActivitySource = 'subagent' | 'job'
+
+/** Deliver one piece of background activity through the host's own feeds. */
+function publishActivity(sidebar: MountedSidebar, source: ActivitySource): void {
+  if (source === 'job') {
+    publishJob(sidebar)
+    return
+  }
+  publishSubagent(sidebar)
+  flushSubagentDebounce()
+}
+
 function publishSubagent(sidebar: MountedSidebar): void {
   const before = sidebar.feed.getSnapshot()
   const sessionId = before.current!
@@ -145,14 +251,44 @@ function publishJob(sidebar: MountedSidebar): void {
   })
 }
 
-function expectSubagentFocused(sidebar: MountedSidebar): void {
+/** Switch the conversation to the child session the Tasks page jumped to. */
+function switchToChild(sidebar: MountedSidebar): void {
+  const before = sidebar.feed.getSnapshot()
+  const parent = before.current!
+  act(() => {
+    sidebar.feed.set({
+      ...before,
+      current: 'child',
+      byId: {
+        ...before.byId,
+        child: {
+          id: 'child',
+          displayTitle: 'Worker',
+          origin: 'subagent',
+          parentId: parent,
+          running: true,
+        },
+      },
+    })
+  })
+}
+
+/** The Tasks page landed in the native right Sidebar (the default open). */
+function expectNativeTasksOpen(sidebar: MountedSidebar, sessionId: string): void {
+  expect(sidebar.surface.opens).toEqual([{
+    sessionId,
+    kind: 'subagent',
+    params: expect.objectContaining({ title: expect.any(String) }),
+    revealIfOpened: true,
+  }])
+}
+
+/** The plugin's own bottom workbench kept its own state and gained no tab. */
+function expectWorkbenchUntouched(sidebar: MountedSidebar, open = false): void {
   const state = sidebar.store.getSnapshot().state!
-  const pane = firstLeaf(state.bottomSplits)
-  expect(state.bottomOpen).toBe(true)
-  expect(state.activePane).toBe(pane.id)
+  expect(state.bottomOpen).toBe(open)
   expect(allLeaves(state.bottomSplits).flatMap(leaf => leaf.tabs)
-    .filter(tab => tab.type === 'subagent')).toHaveLength(1)
-  expect(pane.tabs.find(tab => tab.id === pane.active)?.type).toBe('subagent')
+    .filter(tab => tab.type === 'subagent')).toHaveLength(0)
 }
 
 beforeEach(() => {
@@ -176,33 +312,57 @@ describe('Sidebar background-activity auto-activation (#162)', () => {
     { source: 'job', width: 390 },
     { source: 'subagent', width: 1024 },
     { source: 'job', width: 1024 },
-  ] as const)('$source activation at $width px focuses the Tasks page in the workbench', ({ source, width }) => {
+  ] as const)('$source activation at $width px activates the Tasks page in the native Sidebar', ({ source, width }) => {
     const sidebar = mountSidebar(width)
-    if (source === 'subagent') {
-      publishSubagent(sidebar)
-      flushSubagentDebounce()
-    } else {
-      publishJob(sidebar)
-    }
-    expectSubagentFocused(sidebar)
+    publishActivity(sidebar, source)
+    expectNativeTasksOpen(sidebar, sidebar.sessionId)
+    expectWorkbenchUntouched(sidebar)
+    // Parking is the narrow-viewport half of the same promise.
+    expect(sidebar.column.toggles).toBe(width < 768 ? 1 : 0)
   })
 
-  it.each(['subagent', 'job'] as const)('%s activation keeps an already-open workbench open', (source) => {
-    const sidebar = mountSidebar(390, true)
-    if (source === 'subagent') {
-      publishSubagent(sidebar)
-      flushSubagentDebounce()
-    } else {
-      publishJob(sidebar)
-    }
-    expectSubagentFocused(sidebar)
+  it.each(['subagent', 'job'] as const)('%s activation leaves a narrow fullscreen column to the park', (source) => {
+    const sidebar = mountSidebar(390)
+    publishActivity(sidebar, source)
+    expect(sidebar.column.toggles).toBe(1)
   })
 
-  it('a resize between arming and firing the debounce does not change the landing', () => {
+  it('a narrow column the user already expanded is not closed under them', () => {
+    const sidebar = mountSidebar(390, false, { columnExpanded: true })
+    publishActivity(sidebar, 'subagent')
+    expectNativeTasksOpen(sidebar, sidebar.sessionId)
+    expect(sidebar.column.toggles).toBe(0)
+  })
+
+  it('reads the viewport when the debounced activation fires, not when it arms', () => {
     const sidebar = mountSidebar(1024)
     publishSubagent(sidebar)
     setViewport(390)
     flushSubagentDebounce()
-    expectSubagentFocused(sidebar)
+    expectNativeTasksOpen(sidebar, sidebar.sessionId)
+    expect(sidebar.column.toggles).toBe(1)
+  })
+
+  it('leaves an already-open bottom workbench open and untouched', () => {
+    const sidebar = mountSidebar(1024, true)
+    publishActivity(sidebar, 'subagent')
+    expectNativeTasksOpen(sidebar, sidebar.sessionId)
+    expectWorkbenchUntouched(sidebar, true)
+  })
+
+  it('the topology jump-back opens the Tasks page for the child session and never parks it', () => {
+    const sidebar = mountSidebar(390)
+    // The Tasks page the user opened in the workbench (its own + menu) is what
+    // arms the jump: its node click records the child session.
+    act(() => {
+      sidebar.service.openTab(
+        { type: 'subagent', title: 'Tasks', target: 'bottom' },
+        { sessionId: sidebar.sessionId },
+      )
+    })
+    expect(sidebar.store.getSnapshot().state!.bottomOpen).toBe(true)
+    switchToChild(sidebar)
+    expectNativeTasksOpen(sidebar, 'child')
+    expect(sidebar.column.toggles).toBe(0)
   })
 })