🚀: Compile-time safe state transitions (State Machine DSL)

[Nek-12]

Some libraries (e.g. KStateMachine, Workflow) enforce valid state transitions at compile time or provide strict state machine DSLs to prevent emitting invalid states.

Ideas:

• Provide an overlay, plugin, or an extension DSL for Store that defines valid FromState -> ToState transitions.
• Throw an exception (or fail to compile) if an invalid state is emitted.
• This would be extremely useful for workflows that strictly require a linear or predictable path (e.g. Loading -> Content only, preventing Content -> Loading).