Avoid holding the global loader lock across backend lifecycle waits and propagate forced shutdown through distributed workers. Track parallel requests with in-flight counters and reserve worker ports until process termination.
Add focused race tests and an authoritative FizzBee lifecycle model with a fail-closed conformance target.
Assisted-by: Codex:GPT-5 [FizzBee] [Ginkgo]
Signed-off-by: Richard Palethorpe <io@richiejp.com>