Add the no-project conversation view backed by scratch sessions

Why: Accounts without project.create need isolated general-agent chats.
The sidebar groups every scratch session under one "无项目对话" entry
instead of the project switcher, and the client no longer auto-creates
a default project.

Evidence: npx vitest run (64 files, 677 tests) and npx tsc -b --noEmit
pass locally (SELF); CI on the PR head is authoritative.

Impact: createTask uses POST /api/scratch-sessions in scratch mode or
when no real project exists; scratch rows hide cross-read toggles and
project settings; "新建项目…" stays gated by project.create.

Refs: Agent-System-Dev docs/superpowers/specs/2026-10-22-scratch-session-general-agent-design.md;
agent-exec receipt u3-run5 (cursor, success)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/api.ts

@@ -117,6 +117,7 @@ export const api = {
 	explainSystemAction: (action: string) => auth.fetch(`${BASE}/api/authz/explain?action=${encodeURIComponent(action)}`).then(r => json<{ allowed: boolean; actionId: string; source?: string; reason?: string; authorityEpoch: number }>(r)),
   listProjects: (signal?: AbortSignal) => auth.fetch(`${BASE}/api/projects`, signal ? { signal } : undefined).then(r => json<Project[]>(r)),
   createProject: (name: string) => auth.fetch(`${BASE}/api/projects`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ name }) }).then(r => json<Project>(r)),
+  createScratchSession: (title?: string) => auth.fetch(`${BASE}/api/scratch-sessions`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(title ? { title } : {}) }).then(r => json<{ project: Project; conversation: Conversation }>(r)),
   renameProject: (id: string, name: string) => auth.fetch(`${BASE}/api/projects/${id}`, { method: 'PATCH', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ name }) }).then(r => json<Project>(r)),
   deleteProject: (id: string) => auth.fetch(`${BASE}/api/projects/${id}`, { method: 'DELETE' }).then(checked),
 

src/components/TaskSidebar.tsx

@@ -55,6 +55,7 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
   const artifacts = useStore(s => s.artifacts)
   const currentConvId = useStore(s => s.currentConvId)
   const currentProjectId = useStore(s => s.currentProjectId)
+  const scratchMode = useStore(s => !!s.scratchMode)
   const showArchived = useStore(s => s.ui.showArchived)
   const serverWorkspaces = useStore(s => s.serverWorkspaces)
   /** 审计入口能力门控（增量 2）：命令面探测通过才展示「追溯审计」。 */
@@ -74,13 +75,15 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
 
   const createConversation = async (projectId?: string) => {
     try {
+      if (projectId && scratchMode) await store.openProject(projectId)
       await store.createTask(projectId)
       onConversationOpen?.()
     } catch { /* store owns the actionable failure toast */ }
   }
 
   const tools = buildWorkspaceEntries(serverWorkspaces, { rdmAudit: rdmAuditAvailable, rdmCockpit: rdmCockpitAvailable })
-  const visible = filterTasks(tasks.filter(t => t.projectId === currentProjectId), q)
+  const scratchTasks = tasks.filter(t => t.scratch)
+  const visible = filterTasks(scratchMode ? scratchTasks : tasks.filter(t => t.projectId === currentProjectId && !t.scratch), q)
   const pinned = visible.filter(t => t.pinned)
   const rest = visible.filter(t => !t.pinned)
   const currentProject = projects.find(p => p.id === currentProjectId)
@@ -99,10 +102,10 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
       <button className="tsb-row-act" title={t.archived ? '恢复' : '归档'} onClick={e => { e.stopPropagation(); store.archiveTask(t.id, !t.archived) }}>
         <Icon name={t.archived ? 'undo' : 'archive'} size={13} />
       </button>
-      <button className={`tsb-row-act ${t.crossPrivate ? 'active' : ''}`} title={t.crossPrivate ? '私有会话：不被其他会话读取（点击取消）' : '设为私有（不被其他会话读取）'}
+      {!t.scratch && <button className={`tsb-row-act ${t.crossPrivate ? 'active' : ''}`} title={t.crossPrivate ? '私有会话：不被其他会话读取（点击取消）' : '设为私有（不被其他会话读取）'}
         onClick={e => { e.stopPropagation(); store.setCrossFlags(t.id, { crossPrivate: !t.crossPrivate }) }}>
         <Icon name="shield" size={13} />
-      </button>
+      </button>}
     </span>
   )
 
@@ -121,7 +124,7 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
       <button className="tsb-task-open" onClick={() => { store.openTask(t.id); onConversationOpen?.() }}>
         <Icon name="message" size={14} />
         <span className="tsb-task-t" title={t.title}>{t.title || '未命名对话'}</span>
-        {t.crossPrivate && <span className="tsb-pbadge" title="私有：不被其他会话读取"><Icon name="shield" size={11} /></span>}
+        {t.crossPrivate && !t.scratch && <span className="tsb-pbadge" title="私有：不被其他会话读取"><Icon name="shield" size={11} /></span>}
         <span className="tsb-task-tm">{relativeTime(t.updatedAt)}</span>
       </button>
       {rowActions(t)}
@@ -136,9 +139,9 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
       <div className="tsb-brand">
         <button className="tsb-projrow" title="切换项目"
           onClick={e => { const el = e.currentTarget; setMenu(m => m?.kind === 'project' ? null : { kind: 'project', anchor: el }) }}>
-          <Icon name="folder" size={15} />
-          <span className="tsb-projrow-name">{currentProject?.name ?? '选择项目'}</span>
-          {stage && <span className="tsb-projrow-stage">{stage}</span>}
+          <Icon name={scratchMode ? 'message' : 'folder'} size={15} />
+          <span className="tsb-projrow-name">{scratchMode ? '无项目对话' : currentProject?.name ?? '选择项目'}</span>
+          {stage && !scratchMode && <span className="tsb-projrow-stage">{stage}</span>}
           <span className="tsb-user-chev"><Icon name="chevron-down" size={13} /></span>
         </button>
         <button className="tsb-iconbtn" title="收起侧栏（⌘B）" onClick={onCollapse}><Icon name="panel-left" /></button>
@@ -147,7 +150,8 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
       {/* 主入口创建会话；项目创建保留在次级菜单。 */}
       <div className="tsb-actions">
         <div className="tsb-newtask">
-          <button className="tsb-newtask-main" disabled={noProjects} title={noProjects ? emptyProjectsNotice(projectsLoaded, canCreate) : '在当前项目新建对话（⌘N）'}
+          <button className="tsb-newtask-main" disabled={noProjects && !scratchMode}
+            title={scratchMode ? '新建无项目对话（⌘N）' : noProjects ? emptyProjectsNotice(projectsLoaded, canCreate) : '在当前项目新建对话（⌘N）'}
             onClick={() => createConversation()}>
             <Icon name="plus" size={15} />新建对话
           </button>
@@ -156,12 +160,12 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
         </div>
         <div className="tsb-search">
           <Icon name="search" size={14} />
-          <input aria-label="搜索本项目会话" placeholder="搜索对话…" value={q} onChange={e => setQ(e.target.value)} />
+          <input aria-label={scratchMode ? '搜索无项目对话' : '搜索本项目会话'} placeholder="搜索对话…" value={q} onChange={e => setQ(e.target.value)} />
         </div>
       </div>
 
       <div className="tsb-orgrow">
-        <span className="tsb-seclabel" style={{ padding: 0 }}>本项目会话</span>
+        <span className="tsb-seclabel" style={{ padding: 0 }}>{scratchMode ? '无项目对话' : '本项目会话'}</span>
         <span style={{ flex: 1 }} />
         <button className={`tsb-iconbtn ${showArchived ? 'active' : ''}`} title={showArchived ? '隐藏归档' : '查看归档'}
           onClick={() => { store.setUI({ showArchived: !showArchived }); store.refreshTasks(!showArchived) }}><Icon name="archive" size={15} /></button>
@@ -195,7 +199,8 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
         )}
 
         {rest.length === 0 && pinned.length === 0 && (
-          <div className="tsb-empty">{noProjects ? emptyProjectsNotice(projectsLoaded, canCreate)
+          <div className="tsb-empty">{scratchMode ? '开始一个通用对话；无项目对话彼此独立，不会使用项目文档与知识。'
+            : noProjects ? emptyProjectsNotice(projectsLoaded, canCreate)
             : workError ?? '从「新建对话」开始，描述你想完成的工作。'}</div>
         )}
         {rest.map(t => taskRow(t))}
@@ -215,7 +220,7 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
             <kbd>{entry.shortcut}</kbd>
           </button>
         ))}
-        {currentProject && (
+        {currentProject && !scratchMode && (
           <button className="tsb-tool" onClick={() => store.openProjectSettings(currentProject.id)}>
             <span className="tsb-tool-icon"><Icon name="settings" size={14} /></span>
             <span className="tsb-tool-name">项目设置</span>
@@ -239,6 +244,10 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
 
       {/* 弹出菜单们 */}
       <Menu anchor={menu?.kind === 'project' ? menu.anchor : null} onClose={() => setMenu(null)}>
+        <MenuItem icon="message" onClick={() => { void store.enterScratchMode(); onConversationOpen?.(); setMenu(null) }}>
+          无项目对话
+          <kbd>{scratchMode ? '当前 · ' : ''}{scratchTasks.filter(t => !t.archived).length} 会话</kbd>
+        </MenuItem>
         {projects.map(p => {
           const count = tasks.filter(t => t.projectId === p.id && !t.archived).length
           const pstage = projectStateLabel(p.settings) ?? projectStage(p.settings)
@@ -246,7 +255,7 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
           return (
             <MenuItem key={p.id} icon="folder" onClick={() => { switchProject(p.id); setMenu(null) }}>
               {p.name}
-              <kbd>{p.id === currentProjectId ? '当前 · ' : pstage ? `${pstage} · ` : ''}{mine ? '我创建 · ' : ''}{count} 会话</kbd>
+              <kbd>{p.id === currentProjectId && !scratchMode ? '当前 · ' : pstage ? `${pstage} · ` : ''}{mine ? '我创建 · ' : ''}{count} 会话</kbd>
             </MenuItem>
           )
         })}
@@ -258,12 +267,14 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
       </Menu>
 
       <Menu anchor={menu?.kind === 'new' ? menu.anchor : null} onClose={() => setMenu(null)}>
-        {!noProjects && <MenuItem icon="plus" onClick={() => { createConversation(); setMenu(null) }}>新建对话 · 当前项目<kbd>⌘N</kbd></MenuItem>}
+        {scratchMode
+          ? <MenuItem icon="message" onClick={() => { createConversation(); setMenu(null) }}>新建无项目对话<kbd>⌘N</kbd></MenuItem>
+          : !noProjects && <MenuItem icon="plus" onClick={() => { createConversation(); setMenu(null) }}>新建对话 · 当前项目<kbd>⌘N</kbd></MenuItem>}
         {canCreate && <>
           <div className="tsb-menu-div" />
           <MenuItem icon="folder" onClick={() => { setCreatingProject(true); setMenu(null) }}>新建项目…</MenuItem>
         </>}
-        {noProjects && !canCreate && <div className="tsb-tool-note">{emptyProjectsNotice(projectsLoaded, canCreate)}</div>}
+        {noProjects && !canCreate && !scratchMode && <div className="tsb-tool-note">{emptyProjectsNotice(projectsLoaded, canCreate)}</div>}
         {projects.filter(p => p.id !== currentProjectId).slice(0, 6).map(p => (
           <MenuItem key={p.id} onClick={() => { createConversation(p.id); setMenu(null) }}>在「{p.name}」新建对话</MenuItem>
         ))}
@@ -273,6 +284,8 @@ export function TaskSidebar({ onCollapse = store.toggleLeft, onConversationOpen,
         {rowTask && <>
           <MenuItem icon="pin" onClick={() => { store.pinTask(rowTask.id, !rowTask.pinned); setMenu(null) }}>{rowTask.pinned ? '取消置顶' : '置顶'}</MenuItem>
           <MenuItem icon={rowTask.archived ? 'undo' : 'archive'} onClick={() => { store.archiveTask(rowTask.id, !rowTask.archived); setMenu(null) }}>{rowTask.archived ? '恢复（移出归档）' : '归档'}</MenuItem>
+        </>}
+        {rowTask && !rowTask.scratch && <>
           <div className="tsb-menu-div" />
           <MenuItem icon="shield" onClick={() => { store.setCrossFlags(rowTask.id, { crossPrivate: !rowTask.crossPrivate }); setMenu(null) }}>{rowTask.crossPrivate ? '取消私有（可被其他会话读取）' : '设为私有（不被其他会话读取）'}</MenuItem>
           <MenuItem icon="users" onClick={() => { store.setCrossFlags(rowTask.id, { allowCrossRead: rowTask.allowCrossRead === false }); setMenu(null) }}>{rowTask.allowCrossRead === false ? '开启读取其他会话' : '关闭读取其他会话'}</MenuItem>

src/contracts.ts

@@ -18,6 +18,8 @@ export interface Conversation {
   allowCrossRead?: boolean; crossPrivate?: boolean;
   permissionMode?: 'default' | 'plan' | 'auto_edit' | '';
   sessionNote?: string;
+  /** 无项目对话：服务端内部项目只承载这一条会话，不出现在项目列表里。 */
+  scratch?: boolean;
   createdAt: string; updatedAt: string;
 }
 

src/store.test.ts

@@ -306,14 +306,27 @@ describe('RefreshReconnectCompensate', () => {
   })
 })
 
+function routeScratchSession() {
+  const previous = route
+  route = (path, init) => {
+    if (path === '/api/scratch-sessions' && init?.method === 'POST') {
+      return Promise.resolve(response({ project: project('scratch-1'), conversation: { ...task('scratch-conv', 'scratch-1'), scratch: true } }))
+    }
+    if (path === '/api/conversations/scratch-conv') return Promise.resolve(response({ conversation: { ...task('scratch-conv', 'scratch-1'), scratch: true }, messages: [], runs: [], activeHitl: [], lastSeq: 0 }))
+    return previous(path, init)
+  }
+}
+
 describe('DefaultProjectDisabled', () => {
   it('does not create a default project when the member has no projects yet', async () => {
     projects = []
     await store.refreshProjects()
+    routeScratchSession()
     requests = []
-    await expect(store.createTask()).rejects.toThrow(/等待项目负责人邀请/)
-    expect(requests.filter(r => r.init?.method === 'POST')).toEqual([])
-    expect(store.getState().toast).toMatch(/等待项目负责人邀请/)
+    await store.createTask()
+    const posts = requests.filter(r => r.init?.method === 'POST').map(r => r.path)
+    expect(posts).toEqual(['/api/scratch-sessions'])
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'scratch-conv', currentProjectId: 'scratch-1' })
   })
 
   it('does not treat a list that has not arrived as empty', async () => {
@@ -335,9 +348,12 @@ describe('DefaultProjectDisabled', () => {
     await store.refreshMe()
     projects = []
     await store.refreshProjects()
+    routeScratchSession()
     requests = []
-    await expect(store.createTask()).rejects.toThrow(/请先新建项目/)
+    await store.createTask()
     expect(requests.filter(r => r.path === '/api/projects' && r.init?.method === 'POST')).toEqual([])
+    expect(requests.filter(r => r.init?.method === 'POST').map(r => r.path)).toEqual(['/api/scratch-sessions'])
+    expect(store.getState().projects).toEqual([])
   })
 
   it('surfaces the stage-specific project error before any POST is sent', async () => {

src/store.ts

@@ -3,7 +3,7 @@
 import { useSyncExternalStore } from 'react'
 import { type AdminZoneSection, type LinkedCapabilities, api, connectEvents } from './api'
 import { auth } from './auth'
-import { canCreateProject, noProjectError, projectActionError, projectWorkError } from './projectmeta'
+import { noProjectError, projectActionError, projectWorkError } from './projectmeta'
 import { applyTextDelta, applyThinkingDelta, applyToolCall, applyToolCallDelta, applyToolResult, applyToolOutput, applyArtifactCreated, applyArtifactUpdated, applyCheck, applyFinalizing, type LiveItem } from './live'
 import { closePreviewTab, mergeOrphanPreviewTabs, openPreviewTab, previewTabsKey, type PreviewTab } from './previewtabs'
 import { deliveryRequestId, enqueueMessage, enqueueMessageFront, newQueuedMessage, promoteQueuedMessage, removeQueuedMessage, replaceQueuedText, type QueuedMessage, type WorkReference } from './outbox'
@@ -85,6 +85,8 @@ export interface UIState {
   taskOrg: 'project' | 'timeline'
   showArchived: boolean
   lastProjectId: string | null
+  /** 用户上次停留在无项目对话视图；刷新后回到同一视图。 */
+  lastScratch: boolean
   /** 系统管理全屏视图（阶段② IA：仅管理员；入口账户菜单，纵深防御在 AdminZone 再拦一次）。 */
   adminZoneOpen: boolean
   changePwOpen: boolean
@@ -93,6 +95,11 @@ export interface UIState {
 
 export interface Me { owner: string; name: string; auth: boolean; isAdmin?: boolean; isSuperAdmin?: boolean; mustChangePassword?: boolean; systemActions?: string[]; linkedCapabilities?: LinkedCapabilities }
 
+/** 能否新建真实项目（无项目对话不需要此能力）；服务端仍按当前身份最终判定。 */
+export function canCreateProject(me: Pick<Me, 'auth' | 'systemActions'> | null | undefined): boolean {
+  return !!me && (!me.auth || !!me.systemActions?.includes('project.create'))
+}
+
 /** KTD9 项目自动发现：可见页每 2 秒串行重查；单次请求预算 2 秒、渲染预留 1 秒，正常链路 5 秒内可见。 */
 export const PROJECT_SYNC_INTERVAL_MS = 2000
 export const PROJECT_SYNC_REQUEST_BUDGET_MS = 2000
@@ -107,6 +114,8 @@ interface AppState {
   projectsLoaded: boolean
   projectSync: { status: ProjectSyncStatus; failures: number }
   currentProjectId: string | null
+  /** 无项目对话视图：currentProjectId 此时是无项目对话的内部项目，不在 projects 里。 */
+  scratchMode: boolean
   tasks: Conversation[]
   me: Me | null
   currentConvId: string | null
@@ -181,6 +190,7 @@ filesView: 'list', workspaceSurfacePin: null,
   taskOrg: 'project',
   showArchived: false,
   lastProjectId: null,
+  lastScratch: false,
   adminZoneOpen: false,
   changePwOpen: false,
   projectSettingsId: null,
@@ -210,7 +220,7 @@ const surfaceActionsInflight: Record<string, boolean> = {}
 let state: AppState = {
   contextObs: {},
   projects: [], projectsLoaded: false, projectSync: { status: 'idle', failures: 0 },
-  currentProjectId: null, tasks: [], me: null, currentConvId: null,
+  currentProjectId: null, scratchMode: false, tasks: [], me: null, currentConvId: null,
   messages: [], runs: [], activeHitl: [], lastSeq: 0, live: null,
   plan: null, todos: null, artifacts: [], surfaces: [], projectSurfaces: [], cards: [], projectCards: [], cardActionStates: {}, workRecord: null, workReference: null, inboxScope: 'conv', runtimeMock: false, profiles: [], pluginPanels: [],
   serverWorkspaces: [],
@@ -348,6 +358,29 @@ function resetProjectScope() {
   setUI({ previewExpanded: false, filesView: 'list' })
 }
 
+/** remember=false 用于没有真实项目时的自动进入：不改写用户上次选择的视图。 */
+function setScratchMode(on: boolean, remember = true) {
+  if (state.scratchMode !== on) set({ scratchMode: on })
+  if (remember && state.ui.lastScratch !== on) setUI({ lastScratch: on })
+}
+
+/** 绑定会话所属项目（真实项目或无项目对话的内部项目），供上传与工件归属。 */
+async function bindProject(projectId: string, remember: boolean) {
+  if (state.currentProjectId !== projectId) resetProjectScope()
+  set({ currentProjectId: projectId })
+  if (state.inboxScope === 'project') {
+    store.loadProjectCards()
+    store.connectProject()
+  }
+  if (remember) setUI({ lastProjectId: projectId })
+  await store.refreshArtifacts(projectId)
+}
+
+function latestScratchTask(): Conversation | undefined {
+  return state.tasks.filter(t => t.scratch && !t.archived)
+    .reduce<Conversation | undefined>((latest, t) => !latest || t.updatedAt > latest.updatedAt ? t : latest, undefined)
+}
+
 function observeDetail(observations: Record<string, DetailObservation>, id: string, seq = state.lastSeq, terminal = false) {
   const version = ++detailVersion
   observations[id] = { ...observations[id], version, seq,
@@ -582,18 +615,22 @@ async function mergeProjectList(projects: Project[]) {
   const membershipChanged = !state.projectsLoaded || projectIdsKey(state.projects) !== projectIdsKey(projects)
   set({ projects, projectsLoaded: true, error: null })
   const current = state.currentProjectId
-  if (current && !projects.some(p => p.id === current)) {
+  // 无项目对话视图绑定的是不在列表里的内部项目，列表变化不切换视图。
+  if (state.scratchMode) { /* keep the scratch view */ }
+  else if (current && !projects.some(p => p.id === current)) {
     const fallback = projects[0]
     if (fallback) await store.openProject(fallback.id)
     else {
       resetProjectScope()
       set({ currentProjectId: null })
       setUI({ lastProjectId: null })
+      setScratchMode(true, false)
     }
     store.toast('你已不在原项目中，已清除该项目的入口')
   } else if (!current) {
     const next = projects.find(p => p.id === state.ui.lastProjectId) ?? projects[0]
     if (next) await store.openProject(next.id)
+    else setScratchMode(true, false)
   }
   if (membershipChanged) await store.refreshTasks()
 }
@@ -617,7 +654,7 @@ export const store = {
     for (const key of Object.keys(surfaceActionsInflight)) delete surfaceActionsInflight[key]
     convRestoreDone = true
     persistConvId(null)
-    set({ projects: [], projectsLoaded: false, currentProjectId: null, tasks: [], me: null, currentConvId: null,
+    set({ projects: [], projectsLoaded: false, currentProjectId: null, scratchMode: false, tasks: [], me: null, currentConvId: null,
       contextObs: {}, messages: [], runs: [], activeHitl: [], lastSeq: 0, live: null,
       plan: null, todos: null, artifacts: [], surfaces: [], projectSurfaces: [],
       cards: [], projectCards: [], cardActionStates: {}, workRecord: null, workReference: null, inboxScope: 'conv',
@@ -626,7 +663,7 @@ export const store = {
       rdmDocReviewAvailable: false, rdmPermMatrixAvailable: false, rdmRender: NO_RENDER_CAPABILITIES,
       connected: false, posting: false, error: null, toast: null, outbox: [], outboxDraining: false,
       previewTabs: {}, previewActive: {}, previewOpenIntent: 0 })
-    setUI({ lastProjectId: null, projectSettingsId: null, adminZoneOpen: false, activeWorkspace: null,
+    setUI({ lastProjectId: null, lastScratch: false, projectSettingsId: null, adminZoneOpen: false, activeWorkspace: null,
       settingsOpen: false, changePwOpen: false, trackerRunId: null, workspaceSurfacePin: null,
       previewExpanded: false, filesView: 'list', showArchived: false })
   },
@@ -634,16 +671,23 @@ export const store = {
   async refreshProjects() {
     const epoch = identityEpoch
     const request = ++projectsRequest
+    let scratch = false
     try {
       const projects = await api.listProjects()
       if (epoch !== identityEpoch || request !== projectsRequest) return
+      // 没有真实项目（或上次停留在无项目对话）时进入无项目对话视图，而不是停在空项目上。
+      scratch = projects.length === 0 || state.ui.lastScratch
+      if (scratch) set({ projects, projectsLoaded: true, error: null })
+      else {
         const current = projects.find(p => p.id === state.currentProjectId) ?? projects.find(p => p.id === state.ui.lastProjectId) ?? projects[0]
         set({ projects, projectsLoaded: true, currentProjectId: current?.id ?? null, error: null })
         if (current) await store.openProject(current.id)
+      }
     } catch (e) {
       if (epoch === identityEpoch && request === projectsRequest) set({ error: projectActionError(e) })
     }
     if (epoch === identityEpoch && request === projectsRequest) await store.refreshTasks()
+    if (scratch && epoch === identityEpoch && request === projectsRequest) await store.enterScratchMode(state.ui.lastScratch)
   },
 
   /** 自动发现的一次重查：与 refreshProjects 共用请求代次，迟到/旧身份响应丢弃；失败抛出供退避。 */
@@ -674,14 +718,16 @@ export const store = {
     const request = ++tasksRequest
     try {
       const tasks = await api.listTasks(includeArchived)
-      if (epoch !== identityEpoch || request !== tasksRequest) return
+      if (epoch !== identityEpoch || request !== tasksRequest || !Array.isArray(tasks)) return
       set({ tasks })
       // 首次加载恢复上次会话（仅一次；此后用户主动切换/新建不再打扰）。
       if (!convRestoreDone) {
         convRestoreDone = true
         const saved = savedConvId()
-        if (saved && !state.currentConvId && tasks.some(t => t.id === saved && !t.archived)) {
-          store.openConversation(saved)
+        const restored = saved ? tasks.find(t => t.id === saved && !t.archived) : undefined
+        if (restored && !state.currentConvId) {
+          if (restored.scratch) await store.openTask(restored.id)
+          else store.openConversation(restored.id)
         }
       }
     } catch { /* 列表竞态，静默 */ }
@@ -719,22 +765,41 @@ export const store = {
     }
   },
 
+  /** 打开真实项目：同时离开无项目对话视图。 */
   async openProject(projectId: string) {
-    if (state.currentProjectId !== projectId) resetProjectScope()
-    set({ currentProjectId: projectId })
-    if (store.getState().inboxScope === 'project') {
-      store.loadProjectCards()
-      store.connectProject()
-    }
-    store.setUI({ lastProjectId: projectId })
-    await store.refreshArtifacts(projectId)
+    setScratchMode(false)
+    await bindProject(projectId, true)
+  },
+
+  /** 进入无项目对话视图：当前会话不是无项目对话时清空会话视图，并打开最近一条未归档的无项目对话。 */
+  async enterScratchMode(remember = true) {
+    const epoch = identityEpoch
+    const current = state.tasks.find(t => t.id === state.currentConvId)
+    setScratchMode(true, remember)
+    if (current?.scratch) return
+    if (state.currentProjectId || state.currentConvId) resetProjectScope()
+    set({ currentProjectId: null })
+    const latest = latestScratchTask()
+    if (latest && epoch === identityEpoch) await store.openTask(latest.id)
   },
 
   /** 新建任务（=会话）：默认当前项目上下文；显式 projectId 用于"新建于指定项目"。
-   * 没有项目时不代建「默认项目」：列表未到达或无创建能力时自动建项目会误触权限与同名冲突。 */
+   * 无项目对话视图、或项目列表已到达且没有真实项目时，新建无项目对话；从不代建真实项目。 */
   async createTask(projectId?: string) {
     const epoch = identityEpoch
+    const changed = () => { if (epoch !== identityEpoch) throw new Error('登录状态已变化，请重新选择项目后再试') }
     try {
+      if (state.scratchMode || (!projectId && !state.currentProjectId && state.projectsLoaded && state.projects.length === 0)) {
+        const { conversation } = await api.createScratchSession()
+        changed()
+        setScratchMode(true)
+        await store.refreshTasks()
+        changed()
+        if (!state.tasks.some(t => t.id === conversation.id)) set({ tasks: [{ ...conversation, scratch: true }, ...state.tasks] })
+        await store.openTask(conversation.id)
+        changed()
+        return
+      }
       let pid = projectId ?? state.currentProjectId
       if (!pid && state.projects.length > 0) pid = state.projects[0].id
       if (!pid) throw new Error(noProjectError(state.projectsLoaded, canCreateProject(state.me)))
@@ -761,12 +826,15 @@ export const store = {
     if (title) store.toast('已在当前项目创建任务')
   },
 
-  /** 打开任务：跨项目点击时切换项目上下文（工件/上传归属正确）。 */
+  /** 打开任务：跨项目点击时切换项目上下文（工件/上传归属正确）；视图随任务进入或离开无项目对话。 */
   async openTask(convId: string) {
     const epoch = identityEpoch
     const t = state.tasks.find(x => x.id === convId)
-    if (t && t.projectId !== state.currentProjectId) await store.openProject(t.projectId)
+    if (t?.scratch) {
+      if (t.projectId !== state.currentProjectId) await bindProject(t.projectId, false)
+    } else if (t && t.projectId !== state.currentProjectId) await store.openProject(t.projectId)
     if (epoch !== identityEpoch) return
+    if (t) setScratchMode(!!t.scratch)
     await store.openConversation(convId)
   },
 

test/scratch-session.test.ts

@@ -0,0 +1,129 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { auth } from '../src/auth'
+import { canCreateProject, store } from '../src/store'
+import type { Conversation, Project } from '../src/contracts'
+
+const project = (id: string): Project => ({ id, name: id, createdAt: '', updatedAt: '' })
+const task = (id: string, projectId: string, scratch = false, updatedAt = ''): Conversation =>
+  ({ id, projectId, title: id, createdAt: '', updatedAt, ...(scratch ? { scratch: true } : {}) })
+const response = (value: unknown, status = 200) => new Response(JSON.stringify(value), { status })
+const detail = (conversation: Conversation) => response({ conversation, messages: [], runs: [], activeHitl: [], lastSeq: 0 })
+
+let projects: Project[]
+let tasks: Conversation[]
+let me: Record<string, unknown>
+let requests: { path: string; init?: RequestInit }[]
+let scratchCount: number
+
+const posts = () => requests.filter(r => r.init?.method === 'POST').map(r => r.path)
+
+beforeEach(async () => {
+  projects = []; tasks = []; requests = []; scratchCount = 0
+  me = { owner: 'bob', name: 'Bob', auth: true, systemActions: [] }
+  const saved = new Map<string, string>()
+  vi.stubGlobal('localStorage', { getItem: (key: string) => saved.get(key) ?? null,
+    setItem: (key: string, value: string) => { saved.set(key, value) },
+    removeItem: (key: string) => { saved.delete(key) } })
+  vi.stubGlobal('fetch', async (path: string, init?: RequestInit) => {
+    requests.push({ path, init })
+    if (path === '/api/projects' && !init?.method) return response(projects)
+    if (path === '/api/conversations' && !init?.method) return response(tasks)
+    if (path === '/api/me') return response(me)
+    if (path === '/api/scratch-sessions' && init?.method === 'POST') {
+      const id = `scratch-${++scratchCount}`
+      const conversation = task(`${id}-conv`, id, true)
+      tasks = [conversation, ...tasks]
+      return response({ project: project(id), conversation })
+    }
+    const created = path.match(/^\/api\/projects\/([^/]+)\/conversations$/)
+    if (created && init?.method === 'POST') {
+      const conversation = task(`${created[1]}-new`, created[1])
+      tasks = [conversation, ...tasks]
+      return response(conversation)
+    }
+    const conv = path.match(/^\/api\/conversations\/([^/]+)$/)
+    if (conv && !init?.method) {
+      const found = tasks.find(t => t.id === conv[1])
+      return found ? detail(found) : response({ error: 'not found' }, 404)
+    }
+    if (path.endsWith('/plan') || path.endsWith('/todos')) return response(null)
+    if (path.endsWith('/artifacts') || path.endsWith('/surfaces')) return response([])
+    if (path.endsWith('/cards')) return response({ cards: [] })
+    return response({})
+  })
+  vi.stubGlobal('EventSource', class { addEventListener() {} close() {} })
+  auth.beginSession()
+  await store.refreshMe()
+})
+afterEach(() => { vi.restoreAllMocks(); vi.unstubAllGlobals() })
+
+describe('scratch session entry', () => {
+  it('enters scratch mode for an account without project creation and no projects, and never creates a project', async () => {
+    await store.refreshProjects()
+    expect(store.getState()).toMatchObject({ scratchMode: true, projectsLoaded: true, currentProjectId: null })
+    requests = []
+    await store.createTask()
+    expect(posts()).toEqual(['/api/scratch-sessions'])
+    expect(requests.some(r => r.path === '/api/projects' && r.init?.method === 'POST')).toBe(false)
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'scratch-1-conv', currentProjectId: 'scratch-1', projects: [] })
+  })
+
+  it('always creates a scratch session in scratch mode even when real projects exist', async () => {
+    projects = [project('host-a')]
+    await store.refreshProjects()
+    expect(store.getState()).toMatchObject({ scratchMode: false, currentProjectId: 'host-a' })
+    await store.enterScratchMode()
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentProjectId: null, currentConvId: null })
+    requests = []
+    await store.createTask()
+    await store.createTask()
+    expect(posts()).toEqual(['/api/scratch-sessions', '/api/scratch-sessions'])
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'scratch-2-conv', currentProjectId: 'scratch-2' })
+  })
+
+  it('keeps creating project conversations in project mode', async () => {
+    projects = [project('host-a')]
+    await store.refreshProjects()
+    requests = []
+    await store.createTask()
+    expect(posts()).toEqual(['/api/projects/host-a/conversations'])
+    expect(store.getState()).toMatchObject({ scratchMode: false, currentConvId: 'host-a-new', currentProjectId: 'host-a' })
+  })
+
+  it('returns to the remembered scratch view on reload and opens the latest scratch task', async () => {
+    projects = [project('host-a')]
+    tasks = [task('old', 'scratch-o', true, '2026-01-01'), task('new', 'scratch-n', true, '2026-02-01'), task('work', 'host-a')]
+    await store.refreshProjects()
+    await store.enterScratchMode()
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'new', currentProjectId: 'scratch-n' })
+    expect(store.getState().ui.lastScratch).toBe(true)
+    await store.refreshProjects()
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'new', currentProjectId: 'scratch-n' })
+    await store.openProject('host-a')
+    expect(store.getState()).toMatchObject({ scratchMode: false, currentProjectId: 'host-a' })
+    expect(store.getState().ui.lastScratch).toBe(false)
+  })
+})
+
+describe('scratch mode follows the opened task', () => {
+  it('sets scratch mode for a scratch task and clears it for a normal task', async () => {
+    projects = [project('host-a')]
+    tasks = [task('scratch-conv', 'scratch-1', true), task('work', 'host-a')]
+    await store.refreshProjects()
+    await store.openTask('scratch-conv')
+    expect(store.getState()).toMatchObject({ scratchMode: true, currentConvId: 'scratch-conv', currentProjectId: 'scratch-1' })
+    expect(store.getState().ui.lastProjectId).toBe('host-a')
+    await store.openTask('work')
+    expect(store.getState()).toMatchObject({ scratchMode: false, currentConvId: 'work', currentProjectId: 'host-a' })
+  })
+})
+
+describe('canCreateProject', () => {
+  it('allows project creation without auth or with project.create only', () => {
+    expect(canCreateProject({ auth: false })).toBe(true)
+    expect(canCreateProject({ auth: true, systemActions: ['project.create'] })).toBe(true)
+    expect(canCreateProject({ auth: true, systemActions: [] })).toBe(false)
+    expect(canCreateProject({ auth: true })).toBe(false)
+    expect(canCreateProject(null)).toBe(false)
+  })
+})