fix(tasks): bind cleanup and notices to exact owners

Task records previously retained only ownerSession. If an old agent scope unwound after another agent reused the same agent and session ids, cleanup selected both records and could cancel replacement work. The completion surface also re-resolved the session at settlement, which could inject an old task notice into the replacement agent.

Retain the exact Agent instance for lifecycle work, select owner cleanup by object identity, and pass that exact owner to completion listeners. Keep read, list, kill, and wait authorization session-based as the runtime RFC intends. Add regressions for cleanup and notice routing under id reuse, then update the public docs and generated API catalogs.

packages/tasks/tool-tasks/tests/tool-tasks.spec.ts

@@ -10,6 +10,8 @@ import type { TaskHooks, TaskOutcome, TaskSnapshot, TaskStart } from '@deepseek-
 import * as ToolTasks from '@deepseek-ai/dsh-tool-tasks'
 import { statusLine } from '@deepseek-ai/dsh-tool-tasks'
 
+const agentRegistryDisposers = new WeakMap<Agent, () => void>()
+
 async function setup(config: ToolTasks.Config = {}) {
   const ctx = new Context()
   await ctx.plugin(SystemPrompt)
@@ -21,10 +23,9 @@ async function setup(config: ToolTasks.Config = {}) {
 }
 
 /**
- * A fake agent whose session token is `sessionId`, registered in `ctx.agents`
- * (the notice path finds the owner by scanning the registry for a matching
- * `session.header.id` — the agent id is deliberately DIFFERENT so a
- * wrong-field match fails the test).
+ * A fake agent whose session token is `sessionId`, registered in `ctx.agents`.
+ * The agent id is deliberately different so session authorization and exact
+ * lifecycle ownership cannot be confused in tests.
  */
 function fakeAgent(ctx: Context, sessionId: string, inject: (...args: unknown[]) => void = () => {}): Agent {
   const scopeFiber = ctx.plugin(() => {})
@@ -34,10 +35,16 @@ function fakeAgent(ctx: Context, sessionId: string, inject: (...args: unknown[])
     inject,
     session: { header: { version: 0, id: sessionId, createdAt: 0 } },
   } as unknown as Agent
-  ctx.agents.register(agent)
+  agentRegistryDisposers.set(agent, ctx.agents.register(agent))
   return agent
 }
 
+function detachAgent(agent: Agent): void {
+  const dispose = agentRegistryDisposers.get(agent)
+  if (dispose === undefined) throw new Error(`missing registry disposer for agent "${agent.id}"`)
+  dispose()
+}
+
 /** A controllable producer start-spec (settle `done` on demand, record cancels). */
 function producer(overrides: Partial<Omit<TaskStart, 'run'> & TaskHooks> = {}) {
   let settle!: (outcome: TaskOutcome) => void
@@ -278,6 +285,23 @@ describe('completion notices', () => {
     expect(inject).toHaveBeenCalledTimes(1)
   })
 
+  it('does not route an old owner completion notice to a same-session replacement', async () => {
+    const { ctx } = await setup()
+    const oldInject = vi.fn(() => { throw new Error('agent "agent-shared" is disposed') })
+    const oldOwner = fakeAgent(ctx, 'shared', oldInject)
+    const p = producer({ owner: oldOwner })
+    ctx.tasks.start(p.spec)
+
+    detachAgent(oldOwner)
+    const replacementInject = vi.fn()
+    fakeAgent(ctx, 'shared', replacementInject)
+    p.settle({ status: 'completed' })
+    await tick()
+
+    expect(oldInject).toHaveBeenCalledTimes(1)
+    expect(replacementInject).not.toHaveBeenCalled()
+  })
+
   it('propagates a non-disposed inject failure (a real bug must surface)', async () => {
     const { ctx } = await setup()
     const warn = vi.spyOn(ctx.logger, 'warn').mockImplementation(() => {})
@@ -291,15 +315,15 @@ describe('completion notices', () => {
     expect(warn).toHaveBeenCalledWith(expect.stringContaining('unexpected inject bug'))
   })
 
-  it('drops the notice when no live agent matches and when the agent registry is gone', async () => {
+  it('keeps using the exact owner after the agent registry is gone', async () => {
     const { ctx, agentsFiber } = await setup()
     const inject = vi.fn()
     const owner = fakeAgent(ctx, 'sess-1', inject)
 
-    // Owner known at registration, unregistered before settlement → no match.
+    // Settlement must not depend on a later registry lookup: the exact owner
+    // supplied at start remains the destination while its own scope is live.
     const p1 = producer({ owner })
     ctx.tasks.start(p1.spec)
-    // A second task whose settlement happens after the whole registry is gone.
     const p2 = producer({ owner })
     ctx.tasks.start(p2.spec)
 
@@ -307,6 +331,6 @@ describe('completion notices', () => {
     p1.settle({ status: 'completed' })
     p2.settle({ status: 'failed' })
     await tick()
-    expect(inject).not.toHaveBeenCalled()
+    expect(inject).toHaveBeenCalledTimes(2)
   })
 })