Macro ic_memory_declaration 

macro_rules! ic_memory_declaration {
    (authority = $authority:expr, key = $stable_key:literal $(,)?) => { ... };
}

Register a MemoryManager allocation declaration during static initialization.

The authority names the owner admitted by the host namespace grant. A string literal or shared compile-time string constant may be used. Internal ic-memory authority is unavailable to callers.

This macro only registers declaration metadata. It does not open stable memory. The bootstrap owner still has to collect/seal declarations, validate them against the ledger, commit the generation, and then open memory handles.