Merge remote-tracking branch 'origin/master' into xtr/identified-immutable-messages

# Conflicts:
#	docs/event-producer-consumer.md
#	packages/client/connection/src/client/fixture.ts
#	packages/goal/command-goal/tests/command-goal.spec.ts
#	packages/host/apiproxy/src/api-proxy.ts
#	packages/host/apiproxy/src/api/events.schema.ts
#	packages/host/apiproxy/src/api/events.ts
#	packages/host/apiproxy/tests/api-proxy-view.spec.ts
#	packages/host/apiproxy/tests/rpc-schemas.spec.ts
#	tsconfig.base.json

packages/todo/tool-todo/tests/projection.spec.ts

@@ -0,0 +1,110 @@
+/**
+ * The `todos` projection provider (session-projection RFC knife 4 — the "a
+ * fourth domain is just its own registrations" acceptance probe): mounting
+ * tool-todo beside the registry serves the whole current list on the history
+ * tail page with a consistent asOfSeq (= last event seq); before any write the value is null; a
+ * composition without tool-todo has no `todos` key; unmounting tool-todo
+ * removes it (HMR safety). The carrier and framework are exercised unmodified.
+ */
+
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import AgentRegistry from '@deepseek-ai/dsh-agent'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
+import SessionStore from '@deepseek-ai/dsh-session'
+import type { Session, TodoItem } from '@deepseek-ai/dsh-session'
+import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
+import ToolRegistry from '@deepseek-ai/dsh-tools'
+import SessionProjectionRegistry from '@deepseek-ai/dsh-session-projection'
+import UserInteractionService from '@deepseek-ai/dsh-user-interaction'
+import type { RpcRequest } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
+import { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api/rpc'
+import { createApiProxy } from '@deepseek-ai/dsh-host-apiproxy'
+import * as ToolTodo from '@deepseek-ai/dsh-tool-todo'
+
+let nextRpc = 1
+function request<P>(payload: P): RpcRequest<P> {
+  return { rpcId: RpcId(`todo-proj-${String(nextRpc++)}`), payload }
+}
+
+interface Bench {
+  ctx: Context
+  session: Session
+  tailProjections(): Promise<{ asOfSeq: number; values: Record<string, unknown> } | undefined>
+}
+
+async function harness(withTodoTool: boolean): Promise<Bench> {
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(SystemPrompt, { persona: '' })
+  await ctx.plugin(ToolRegistry)
+  await ctx.plugin(UserInteractionService)
+  await ctx.plugin(AgentRegistry)
+  await ctx.plugin(SessionProjectionRegistry)
+  if (withTodoTool) await ctx.plugin(ToolTodo)
+  const session = ctx.sessions.create()
+  ctx.agents.register({ id: session.id, session, status: 'idle', ctx } as Agent)
+  const api = createApiProxy(ctx, { provider: 'p', model: 'm', cwd: '/tmp', workspaceRoot: '/tmp' })
+  return {
+    ctx,
+    session,
+    async tailProjections() {
+      const response = await api.sessions.history(request({ sessionId: session.id }))
+      if (!response.result.ok) throw new Error('history failed')
+      return response.result.value.projections
+    },
+  }
+}
+
+/** One paginable message so the tail page is non-degenerate. */
+function seedMessage(session: Session): void {
+  session.append('user/message', createUserMessage({
+    content: [{ type: 'text', text: 'hi' }],
+    source: { kind: 'user' },
+  }), { surfaceOp: 'append' })
+}
+
+describe('todos projection provider', () => {
+  it('serves null before the first todo/write', async () => {
+    const bench = await harness(true)
+    seedMessage(bench.session)
+    const projections = await bench.tailProjections()
+    expect(projections?.values).toEqual({ todos: null })
+    expect(projections?.asOfSeq).toBe(bench.session.seq - 1)
+  })
+
+  it('serves the latest whole list after writes, asOfSeq = last event seq', async () => {
+    const bench = await harness(true)
+    const session = bench.session
+    seedMessage(session)
+    const first: TodoItem[] = [{ content: 'a', status: 'pending' }]
+    const second: TodoItem[] = [
+      { content: 'a', status: 'completed' },
+      { content: 'b', status: 'in_progress' },
+    ]
+    session.append('todo/write', { todos: first })
+    session.append('todo/write', { todos: second })
+    const projections = await bench.tailProjections()
+    // Last-wins: the latest snapshot, whole.
+    expect(projections?.values.todos).toEqual(second)
+    expect(projections?.asOfSeq).toBe(session.seq - 1)
+  })
+
+  it('has no todos key when tool-todo is not composed', async () => {
+    const bench = await harness(false)
+    seedMessage(bench.session)
+    const projections = await bench.tailProjections()
+    expect(projections).toBeDefined()
+    expect('todos' in (projections?.values ?? {})).toBe(false)
+  })
+
+  it('drops the key when the tool-todo fiber unloads (HMR safety)', async () => {
+    const bench = await harness(false)
+    seedMessage(bench.session)
+    const fiber = await bench.ctx.plugin(ToolTodo)
+    expect((await bench.tailProjections())?.values).toEqual({ todos: null })
+    await fiber.dispose()
+    expect('todos' in ((await bench.tailProjections())?.values ?? {})).toBe(false)
+  })
+})