feat(browser-pools): typed acquire helper distinguishing got / timed-out

[Jayko001]

Summary

Adds a typed wrapper around client.browserPools.acquire so callers can distinguish a successful lease from a long-poll timeout without inspecting raw HTTP status codes.

import Kernel, { acquireBrowserFromPool } from '@onkernel/sdk';

const result = await acquireBrowserFromPool(client, 'my-pool');
if (result.status === 'acquired') {
  useBrowser(result.browser);
} else {
  // status === 'timed_out' — retry to keep waiting
}

• { status: 'acquired', browser } — 200, browser leased from pool
• { status: 'timed_out' } — 204, long poll expired, retry
• NotFoundError — 404, pool does not exist (existing exception, propagated)

The generated client.browserPools.acquire() method is unchanged for backwards compatibility.

Test plan

• Unit tests cover 200 / 204 / 404 paths
• Lint + typecheck clean
• Manual smoke test against staging once published