@cloudflare/sandbox@0.12.5

• #786 750ca4d Thanks @aron-cf! - Instrument the bridge API with Cloudflare custom spans. Each endpoint now emits
  a bridge.<operation> span annotated with the sandbox ID, container UUID, and
  operation-specific metadata (command, file path, port, session ID, and so on),
  so requests are traceable end to end. Enable tracing with
  observability.traces.enabled in your Worker configuration.

• #799 0783596 Thanks @aron-cf! - Make destroy() succeed when the sandbox container was never admitted, so cleanup no longer fails with a no-instance platform error.

• #799 0783596 Thanks @aron-cf! - Reduce intermittent startup failures during concurrent sandbox creation where operations could fail with a disposed RPC session error.

• #799 0783596 Thanks @aron-cf! - Surface container capacity and admission failures as retryable ContainerUnavailableError with a structured reason, including no-instance and max-instances cases. Callers can branch on error.reason instead of parsing platform messages.

• #786 750ca4d Thanks @aron-cf! - Fill the warm pool in bounded-parallel batches instead of one container at a
  time, so it primes and recovers far faster after a burst. Tune the batch size
  with WARM_POOL_SCALE_BATCH_SIZE (default 5, clamped to 20).

• #786 750ca4d Thanks @aron-cf! - Refill the warm pool the moment it drains instead of waiting for the next
  background tick. After a burst consumes warm containers, replenishment now
  starts immediately, cutting the latency tail for sandboxes created during
  sustained or back-to-back bursts.

• #786 750ca4d Thanks @aron-cf! - Let the warm pool know its instance ceiling up front via the
  WARM_POOL_MAX_INSTANCES bridge variable. Set it to match your container's
  max_instances so the pool makes correct capacity decisions without first
  crashing into the limit. 0 (the default) preserves the existing auto-learn
  behaviour.