fix: give each configureManualApproval call its own approval client

[breken-ai]

What is the current behavior?

OneCLI creates one ApprovalClient in its constructor, and every configureManualApproval call starts that same instance. stop() sets the shared running flag to false and aborts the current poll.

If you stop a handle and then call configureManualApproval again, for example to swap the callback, the new start() sets running back to true synchronously, before the stopped loop has seen the aborted poll. When the stopped loop gets to its catch, if (!this.running) return is false, so it backs off for 5s and keeps polling. After that, both loops take pending approvals, and the stopped handle's callback keeps deciding some of them. In the test below, it denies a request that the new callback would have approved.

The stopped loop also overwrites the shared abortController, so a later stop() aborts only one of the two polls.

What is the new behavior?

Each configureManualApproval call gets its own ApprovalClient, and the handle stops that client. org.configureManualApproval already works this way. A stopped handle stays stopped, whatever other calls do afterwards.

This is independent of #58, which moves the gateway URL resolution into the poll loop. The two PRs touch different files.

Additional context

test/approvals/configure.test.ts registers a callback, stops it, registers a second one, and then answers every poll that is still open with one pending request. It checks that only the second callback receives the request.

Checked locally on Node 22 with pnpm 10.30.1:

Check	Result
New test against unpatched main (6579233)	failed: the stopped callback got ap-1
New test with this change	passed
pnpm test	132 passed (11 files)
pnpm typecheck	passed
pnpm build	passed

Not tested against a running OneCLI instance.