Summary

• Adds a "pooled" resource scope — a bounded checkout/return pool per resource, implementing the cross-SDK pooled-resource contract.
• New ResourcePool with a private promise-based FIFO semaphore (per-waiter unref'd timeout, waiter removed on timeout so a later permit goes to a live caller). Checkout waits up to acquireTimeoutMs (default 10s) then throws the new ResourceUnavailableError; idle instances are reused until maxLifetimeMs evicts them; active moves only after the factory resolves and the permit is returned on factory rejection, so capacity never leaks. Prewarm tops the idle list up to poolMin (idempotent across worker leases) and is best-effort.
• Registration: queue.resource(name, factory, { scope: "pooled", pool: { poolSize, poolMin, acquireTimeoutMs, maxLifetimeMs } }); pool options without the pooled scope are rejected.
• Runtime: one checkout per task per resource (pending checkout cached before awaiting, so concurrent resolves share it); task teardown releases back to the pool — never disposes; worker teardown shuts pools down before worker resources; created/disposed metrics move only on actual build/eviction/shutdown.
• Guard: a pooled factory may only use worker-scoped dependencies — pooled instances outlive tasks (ResourceScopeError message now names both scopes).
• Docs: pooled scope added to the resources guide and dependency-injection page.

Test plan

• 15 new tests: 6 ResourcePool unit (reuse, timeout, capacity safety, prewarm, lifetime eviction, stats), 5 runtime-level, 4 worker-integration.
• pnpm typecheck, pnpm lint, full suite 263 tests green; docs types:check + lint green.