…orkflows

…orkflows

…pace packages

…ol-labs

…hooks

… hints

…ncerContext in public API; Update load balancer docstrings

…very, loadbalancer, and routine subpackages

…er subpackage README

…in relevant LLM skills

Correct return type annotations and narrowing issues caught by
pyright across the runtime subpackages:

- roundrobin: Use AsyncGenerator instead of AsyncIterator for dispatch
- task: Add casts for generic W return type and runtime assertions
  for callable type narrowing
- connection: Annotate _execute return type and cast the generator
  in dispatch to satisfy AsyncGenerator variance
- pool: Narrow overload 1 discovery parameter to None to prevent
  overlap with the discovery-required overload; add third overload
  for hybrid pools that both spawn local workers and discover
  remote workers