Module pool 

Pool state (Phase H.4) reducer handlers. Extracted from reducer/mod.rs in task #182 PR-F-2 for navigability.

Functions

handle_pool_destroyed_before_promote 🔒

handle_pool_drain_all 🔒

handle_pool_ready 🔒

handle_pool_spawn_start 🔒

handle_pop_and_promote_front_pool_window 🔒

handle_promote_pool_window 🔒