refactor(gui): todos ride the generic projection pair; ConversationSnapshot evacuated

TodoDock reads useProjection('todos') (whole list or null pre-first-write;
absent renders nothing) and declare-merges the todos key through the pure-type
outlet — the identical member the tool-todo host unit owns, drift rejected by
any program holding both. The core Session's todos field, its todo/write case,
and the snapshot member retire; the client folds nothing. Session specs for
the retired client fold move to the value-store spec's seq coverage; snapshot
literals across component specs drop the field.

packages/client/runtime/src/client/sessions/conversation.ts

@@ -269,7 +269,4 @@ export interface ConversationSnapshot {
    */
   blank: boolean
   lastAgentError: string | null
-  /** Current whole-list `todo/write` projection — the tail page's full-log value, then each live
-   *  write (last write wins); empty = the log holds no plan. */
-  todos: readonly TodoItem[]
 }

packages/client/runtime/tests/event-script.ts

@@ -40,8 +40,6 @@ export const ev = {
     at(seq, { type: 'step/end', data: { turn, step } }),
   turnEnd: (seq: number, turn: number, reason: 'completed' | 'cancelled' = 'completed'): SessionEvent =>
     at(seq, { type: 'turn/end', data: { turn, reason: { kind: reason } } }),
-  todoWrite: (seq: number, todos: { content: string; status: 'pending' | 'in_progress' | 'completed' }[]): SessionEvent =>
-    at(seq, { type: 'todo/write', data: { todos } }),
   commandRun: (seq: number, commandId: string, name: string, args = ''): SessionEvent =>
     at(seq, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } }),
   commandDone: (seq: number, commandId: string, kind: 'success' | 'error' = 'success', text?: string): SessionEvent =>

packages/client/runtime/tests/fake-api.ts

@@ -62,7 +62,7 @@ export class FakeApiClient implements IApiClient {
   onList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
   onCreate: (payload: unknown) => Promise<RpcResponse<{ sessionId: SessionId }>> = () => Promise.resolve(ok({ sessionId: 'fk-new' as SessionId }))
   onHistory: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number })
-  => Promise<RpcResponse<{ events: never[]; hasMore: boolean; todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[] }>> =
+  => Promise<RpcResponse<{ events: never[]; hasMore: boolean }>> =
     () => Promise.resolve(ok({ events: [], hasMore: false }))
 
   onPrompt: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))

packages/client/runtime/tests/session.spec.ts

@@ -22,9 +22,9 @@ function makeSession(api = new FakeApiClient()): { api: FakeApiClient; session:
   return { api, session: new Session(SID, api) }
 }
 
-function histResponse(events: SessionEvent[], hasMore = false, todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[]) {
+function histResponse(events: SessionEvent[], hasMore = false) {
   // history now returns HistoryEntry[] ({event, view?}); these tests are view-less.
-  return Promise.resolve(ok({ events: entries(events) as never[], hasMore, ...todos === undefined ? {} : { todos } }))
+  return Promise.resolve(ok({ events: entries(events) as never[], hasMore }))
 }
 
 describe('open', () => {
@@ -175,42 +175,6 @@ describe('live event path', () => {
     })
   })
 
-  it('folds todo/write into snapshot.todos last-write-wins, live and on window replay', async () => {
-    const listA = [{ content: '搭骨架', status: 'completed' as const }, { content: '写组件', status: 'in_progress' as const }]
-    const listB = [{ content: '搭骨架', status: 'completed' as const }, { content: '写组件', status: 'completed' as const }]
-    const { session } = await opened()
-    expect(session.getSnapshot().todos).toEqual([])
-    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
-    feed(ev.todoWrite(6, listA))
-    expect(session.getSnapshot().todos).toEqual(listA)
-    feed(ev.todoWrite(7, listB))
-    expect(session.getSnapshot().todos).toEqual(listB)
-    // Window replay converges on the same last snapshot (history contains both writes).
-    const replayed = makeSession()
-    replayed.api.onHistory = () => histResponse([...plainTurn(0, 0, 'a', 'b'), ev.todoWrite(6, listA), ev.todoWrite(7, listB)])
-    await replayed.session.open()
-    expect(replayed.session.getSnapshot().todos).toEqual(listB)
-  })
-
-  it('seeds todos from the tail page projection when the last write precedes the window', async () => {
-    const list = [{ content: '窗口外的计划', status: 'in_progress' as const }]
-    // Cold open: the page window carries NO todo/write; the projection rides the response.
-    const { api, session } = makeSession()
-    api.onHistory = () => histResponse(plainTurn(100, 9, '问', '答'), true, list)
-    await session.open()
-    expect(session.getSnapshot().todos).toEqual(list)
-    // Paging an older window in must not clear the session-level projection.
-    api.onHistory = () => histResponse(plainTurn(94, 8, '旧问', '旧答'), false)
-    await session.loadOlder()
-    expect(session.getSnapshot().todos).toEqual(list)
-    // A later live write still overrides the seeded projection.
-    session.handleMuxEnvelope('r' as never, {
-      type: 'session/event', sessionId: SID,
-      event: ev.todoWrite(106, [{ content: '新计划', status: 'pending' as const }]),
-    })
-    expect(session.getSnapshot().todos).toEqual([{ content: '新计划', status: 'pending' }])
-  })
-
   it('repairs a seq gap by repulling the tail page instead of appending a hole', async () => {
     const { api, session } = await opened(plainTurn(0, 0, 'a', 'b')) // tail seq = 5
     const repaired = [...plainTurn(0, 0, 'a', 'b'), ...plainTurn(6, 1, 'c', 'd')]
@@ -224,37 +188,6 @@ describe('live event path', () => {
     const seqs = session.getSnapshot().nodes.map(n => n.seq)
     expect(seqs).toEqual([1, 3, 7, 9]) // both turns' user/assistant, no hole, no duplicate 9
   })
-
-  it('gap repair adopts the repull response projection (a missed todo/write outside the new tail page)', async () => {
-    const { api, session } = await opened(plainTurn(0, 0, 'a', 'b')) // tail seq = 5
-    expect(session.getSnapshot().todos).toEqual([])
-    // The missed range contained a todo/write that the repulled page no longer
-    // covers; the response's session-level projection is the only carrier.
-    const current = [{ content: '断线期间写的', status: 'in_progress' as const }]
-    api.onHistory = () => histResponse([...plainTurn(0, 0, 'a', 'b'), ...plainTurn(8, 1, 'c', 'd')], false, current)
-    session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event: ev.assistant(11, 1, 'd') })
-    await vi.waitFor(() => {
-      expect(api.callsOf('session.history').length).toBe(2)
-    })
-    await Promise.resolve()
-    expect(session.getSnapshot().todos).toEqual(current)
-  })
-
-  it('clears the plan when a tail response omits the projection (a write the log never kept)', async () => {
-    // Live write lands, then the host crashes before persisting it: the
-    // authoritative log holds no todo/write, so the resync tail response
-    // carries no projection — an omitted field on a tail request is the empty
-    // list, not a missing carrier, and the rolled-back plan must disappear.
-    const { api, session } = await opened(plainTurn(0, 0, 'a', 'b'))
-    session.handleMuxEnvelope('r' as never, {
-      type: 'session/event', sessionId: SID,
-      event: ev.todoWrite(6, [{ content: '丢失的计划', status: 'in_progress' as const }]),
-    })
-    expect(session.getSnapshot().todos).toEqual([{ content: '丢失的计划', status: 'in_progress' }])
-    api.onHistory = () => histResponse(plainTurn(0, 0, 'a', 'b'))
-    await session.resync()
-    expect(session.getSnapshot().todos).toEqual([])
-  })
 })
 
 describe('paging', () => {

packages/client/ui-conversation/package.json

@@ -49,6 +49,7 @@
   },
   "devDependencies": {
     "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
     "@deepseek-ai/dsh-client-ui-layout": "workspace:^",
     "@deepseek-ai/dsh-client-ui-primitives": "workspace:^",
     "@deepseek-ai/dsh-client-ui-slash": "workspace:^",

packages/client/ui-conversation/src/client/skeleton/TodoPanel.tsx

@@ -9,6 +9,17 @@ import { useId, useState } from 'react'
 import type { Context } from 'cordis'
 import type { PropsRuntime } from '@deepseek-ai/dsh-client-ui-slots'
 import type { TodoItem } from '@deepseek-ai/dsh-client-runtime/client'
+
+// Client-side view of the todos projection key. The authoritative merge lives
+// with the domain host unit (tool-todo), whose program never overlaps the
+// client's, so this consumer restates the identical member through the same
+// pure-type outlet (any program holding both merges rejects drift).
+declare module '@deepseek-ai/dsh-session-projection/types' {
+  interface SessionProjectionMap {
+    /** The agent's current whole todo list (latest `todo/write` snapshot), or `null` before the first write. */
+    todos: TodoItem[] | null
+  }
+}
 import { IconChevronDownOutline14, IconChevronUpOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
 import css from './TodoPanel.module.css'
 
@@ -115,10 +126,10 @@ export function TodoPanel({ todos }: TodoPanelProps) {
 /** Full props of a dock entry: InputZone owner share + session standard kit + global seat. */
 export type TodoDockProps = PropsRuntime<'conversation.input.dock'>
 
-/** Dock adapter: selects the plan off the session snapshot and hands the strip a plain list. */
+/** Dock adapter: reads the host-computed 'todos' projection (whole list; absent or null renders nothing). */
-export function TodoDock({ useSession }: TodoDockProps) {
+export function TodoDock({ useProjection }: TodoDockProps) {
-  const todos = useSession(s => s.todos)
+  const todos = useProjection('todos')
-  return <TodoPanel todos={todos} />
+  return <TodoPanel todos={todos ?? []} />
 }
 
 /**

packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx

@@ -56,7 +56,7 @@ function snapshotWith(
 ): ConversationSnapshot {
   return {
     sessionId: SID, nodes, foldDegraded: false, partial: null, runningCalls, codeDispatches,
-    pending: [], queue: [], todos: [], running: runningCalls.length > 0, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: runningCalls.length > 0, composerPhase: 'active', removed: false,
     openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -27,7 +27,7 @@ const assistant = (seq: number, turn: number, usage?: unknown): AssistantMessage
 function snapshotBase(): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }
 }

packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx

@@ -40,7 +40,7 @@ const toolResult = (seq: number, callId: string, name: string, args = '{"command
 function snapshotWith(nodes: ToolResultNode[]): ConversationSnapshot {
   return {
     sessionId: SID, nodes, foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }
 }

packages/client/ui-conversation/tests/chat-view.spec.tsx

@@ -30,7 +30,7 @@ const SID = 's1' as SessionId
 function snapshotBase(): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }
 }

packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx

@@ -19,7 +19,7 @@ const SID = 's1' as SessionId
 function snapshotBase(): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }
 }

packages/client/ui-conversation/tests/input-bar.spec.tsx

@@ -21,7 +21,7 @@ const SID = 's1' as SessionId
 function snapshotOf(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,
     ...overrides,

packages/client/ui-conversation/tests/input-matrix.spec.tsx

@@ -24,7 +24,7 @@ const SID = 's1' as SessionId
 function mountBar(shell: SessionInputShell, over?: { running?: boolean; disabled?: boolean }) {
   const session = createSnapshotStore<ConversationSnapshot>({
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: over?.running ?? false, composerPhase: 'active',
+    pending: [], queue: [], running: over?.running ?? false, composerPhase: 'active',
     removed: over?.disabled ?? false, openState: 'open', openError: null, hasMore: false,
     loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   })

packages/client/ui-conversation/tests/input-scenarios.spec.tsx

@@ -110,7 +110,7 @@ async function scopedBench(register?: (slash: SlashService) => void) {
   const wiring = shell
   const sessionStore = createSnapshotStore<ConversationSnapshot>({
     sessionId, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,
   })

packages/client/ui-conversation/tests/queue-dock.spec.tsx

@@ -19,7 +19,7 @@ const SID = 's1' as SessionId
 function snapshotWith(queue: QueuedMessage[]): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue, todos: [], running: true, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue, running: true, composerPhase: 'active', removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null,
   }
 }

packages/client/ui-conversation/tests/skeleton.spec.tsx

@@ -48,7 +48,7 @@ const workspaceState = (items: readonly WorkspaceView[]): WorkspaceListState =>
 function conversationSnapshot(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
   return {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
     openState: 'open', openError: null, hasMore: false, loadingOlder: false,
     promptError: null, blank: false, lastAgentError: null,
     ...overrides,

packages/client/ui-conversation/tests/todo-panel.spec.tsx

@@ -64,20 +64,23 @@ describe('TodoPanel', () => {
   })
 })
 
-/** Dock props stub: the adapter reads useSession only; the rest of the owner share is unused. */
+/** Dock props stub: the adapter reads the 'todos' projection only; the rest of the owner share is unused. */
-function dockProps(store: ReturnType<typeof createSnapshotStore<{ todos: readonly TodoItem[] }>>): TodoDockProps {
+function dockProps(store: ReturnType<typeof createSnapshotStore<{ value: readonly TodoItem[] | null | undefined }>>): TodoDockProps {
-  return { useSession: bindSnapshotSelector(store) } as unknown as TodoDockProps
+  const useProjection = (_key: string, selector?: (v: unknown) => unknown) =>
+    bindSnapshotSelector(store)(s => (selector ?? (v => v))(s.value))
+  return { useProjection } as unknown as TodoDockProps
 }
 
 describe('TodoDock', () => {
-  it('selects the plan off the session snapshot and follows later writes', () => {
+  it('reads the host-computed todos projection and follows pushed updates', () => {
-    const store = createSnapshotStore<{ todos: readonly TodoItem[] }>({ todos: [] })
+    const store = createSnapshotStore<{ value: readonly TodoItem[] | null | undefined }>({ value: undefined })
     render(<TodoDock {...dockProps(store)} />)
+    // Capability absent (no baseline/frame yet) renders nothing.
     expect(screen.queryByTestId('todo-panel')).toBeNull()
-    act(() => { store.set({ todos: LIST }) })
+    act(() => { store.set({ value: LIST }) })
     expect(screen.getByText('1/3 tasks · 1 in progress')).toBeTruthy()
-    // A rollback to the empty list retires the strip (the panel owns no data).
+    // The pre-first-write whole value (null) retires the strip (the panel owns no data).
-    act(() => { store.set({ todos: [] }) })
+    act(() => { store.set({ value: null }) })
     expect(screen.queryByTestId('todo-panel')).toBeNull()
   })
 

packages/client/ui-conversation/tsconfig.json

@@ -23,6 +23,9 @@
     {
       "path": "../runtime"
     },
+    {
+      "path": "../../session-projection/session-projection"
+    },
     {
       "path": "../ui-slash"
     },