Kudzu 0.8.50 - Package-neutral shared state IR
Kudzu 0.8.50 isolates reduced Zustand migration behind validated SharedStateIR and SharedActionIR records before generic signal and handler consumers. Existing RouteIR layout ownership, same-turn action updates, enhanced-navigation persistence, and Zustand source diagnostics remain unchanged. No public store or compatibility-adapter API, subscription system, or generic browser store runtime is added.