Pin plugin Runner cleanup to its physical task (#19300)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - Plugin Runner owners manage a physical task through an environment
lease.
> - The existing replacement path can assign a new physical task to that
same lease.
> - A delayed old owner can then stop the replacement or mark it
stopped.
> - Cleanup must keep the original physical task identity across RPC and
database writes.
> - This pull request pins that identity and keeps cleanup available to
the new owner.

## Linked Issues or Issue Description

Refs #19134 and #19157. This fix is based on master and does not enable
repeated stopped-source recovery. A search found no duplicate fix.

**What happened?**

The maintained `createOwnedSandbox` replacement path changes
`providerLeaseId` on one lease. An old task owner uses that mutable
lease for a later Stop. A stopped-state response already in flight can
also update the new task's flags.

**Expected behavior**

The old owner must address its original task. Its late cleanup writes
must not alter the replacement. The replacement's own owner must still
stop and complete it.

**Steps to reproduce**

1. Create a plugin task owner for a stopped task.
2. Replace that task through the existing describe/startup path on the
same lease.
3. Resume an old checkpoint or a held old status response.
4. Observe a Stop for the replacement or an incorrect stopped flag
before this fix.

## What Changed

- Require each task owner to keep the physical ID returned by its
description. Reject a rebind to a different task.
- Carry the ID through the existing internal task context after startup
ends. Reject a changed physical task before RPC dispatch.
- Match the physical task in stopped-state, completion and
credential-handoff writes.
- Hold the exact lease row through the retained-session database update
and local checkpoint save.
- Cover the maintained replacement path with real PostgreSQL tests.
Preserve positive cleanup for the replacement owner. Document this
boundary.

## Verification

- Both replacement regressions failed on unmodified master `10a7d039c8`:
delayed old-owner Stop targeted the replacement, and a held old status
response marked it stopped.
- Six focused files passed 160 tests: task authority, task runtime, warm
tasks, execution target, credential writeback and task owner.
- Four selected executor factory cases passed. They cover task-only
providers and the physical task binding after the startup context ends.
- Runner TypeScript, plugin SDK and adapter-utils builds passed. Server
TypeScript check passed. Diff and added-line secret scans passed.
- All 15 setup-probe cases passed with the actual Runner and fake
provider binaries. The first local attempt lacked cargo on PATH. A
sandboxed native attempt timed out in seven process cases; the unchanged
run with loopback permission passed all 15. A separate initial DB
integration attempt was denied a loopback listener; its
permission-correct run passed.
- Review found three missed constructors in the existing SDK/Core
lifecycle fixture. They now use the actual describe result. All four
cases in that real PostgreSQL and worker RPC file passed.
- The first GitHub attempt failed in the unchanged GitHub recovery
pagination case in `chat-channels.integration.test.ts`: its zero-request
assertion observed a configuration GET. That exact case passed locally
without code or assertion changes. The one failed-job-only retry passed;
the initial failure log is retained.
- [GitHub workflow
42082587576](https://github.com/paperclipai/paperclip/actions/runs/42082587576)
passed on its second attempt. All CI checks completed, and Snyk passed.
Standard Greptile scored exact head `fb914d98b99e` 5/5 with no
unresolved threads. The branch is mergeable and ready for review.

## Risks

The task context change is internal. It adds no plugin wire field,
schema or Runner mode. A stale owner now gets an error and cannot clean
up a replacement. A new owner can still clean up that task. The retained
checkpoint write holds one existing lease row during a bounded local
file write.

Repeated stopped-source incarnation admission, runtime pins and
deployments are outside this change.

## Model Used

OpenAI GPT-6.1 Sol (`gpt-6.1-sol`), high reasoning. Used repository
tools, TypeScript and real PostgreSQL tests.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used with version and capability
details
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have described the issue in-PR using the bug template
- [x] I have not referenced internal or instance-local Paperclip issues
or links
- [x] My branch name describes the change
- [x] I have run the focused tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation
- [x] I have considered and documented risks
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no unresolved findings
- [x] I will address reviewer comments before requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

server/src/services/native-runtime/plugin-runner-task.ts

@@ -29,7 +29,8 @@ export async function verifyPluginRunnerTaskReattachment(
  */
 export function createPluginRunnerTaskOwner(input: {
   executionContext?: NativeExecutionContext;
-  task: (operation: unknown) => Promise<unknown>;
+  taskId: string;
+  task: (operation: unknown, options?: { expectedTaskId?: string }) => Promise<unknown>;
   projectIds: readonly string[];
   harness: string;
   projectAuthCheckVersion?: 1;
@@ -46,6 +47,8 @@ export function createPluginRunnerTaskOwner(input: {
   githubBroker?: { url: string; token: string };
   adoptIdentity?: DurableRecoveryIdentity;
 }) {
+  const taskId = input.taskId;
+  if (!taskId) throw new Error("Plugin Runner physical task unavailable");
   const pollMs = input.pollMs ?? 500;
   let registrationGeneration = 0;
   let activeOutbound: ReturnType<typeof connectRunnerPrpIngress> | null = null;
@@ -72,7 +75,7 @@ export function createPluginRunnerTaskOwner(input: {
     const phase = ({ prepare: "execution.plugin_prepare", check_project_auth: "execution.plugin_project_auth",
       submit: "execution.plugin_submit", connection: "execution.plugin_connection" } as const)[operation.kind as "prepare" | "check_project_auth" | "submit" | "connection"];
     const result = environmentTaskResultSchema.parse(await (phase
-      ? measureRunPhase(phase, () => input.task(operation)) : input.task(operation)));
+      ? measureRunPhase(phase, () => input.task(operation, { expectedTaskId: taskId })) : input.task(operation, { expectedTaskId: taskId })));
     if (result.kind !== (operation.kind === "read_file" ? "file" : operation.kind === "describe" ? "description" : operation.kind === "prepare" ? "prepared" : operation.kind === "check_project_auth" ? "project_auth" : ["read_state", "archive_state"].includes(operation.kind) ? "state" : ["status", "connection", "credentials"].includes(operation.kind) ? operation.kind : "accepted")) {
       throw new Error("Plugin Runner returned an invalid operation result");
     }
@@ -353,7 +356,7 @@ export function createPluginRunnerTaskOwner(input: {
     // stop request. Completion also proves credential/writeback obligations ran.
     isRetired: () => stoppedState?.executionStopped === true && completed && !detached,
     rebind(next: typeof input) {
-      if (!launched || stopRequested || stoppedState || detached || next.harness !== input.harness ||
+      if (!launched || stopRequested || stoppedState || detached || next.taskId !== taskId || next.harness !== input.harness ||
           input.accountIdentity !== next.accountIdentity || input.credentialIdentity !== next.credentialIdentity ||
           JSON.stringify(input.projectIds) !== JSON.stringify(next.projectIds)) throw new Error("Plugin warm task cannot be rebound");
       input = next;