docs(persistence): warn against resolving IEntityStore from the DI container

The store is intentionally never registered in the container and its
implementation has an internal constructor, so direct registration or
resolution fails at runtime; the remarks now point callers to
RegisterPersistedEntity plus IPersistenceService.GetStore.

Author: tgiachi

src/SquidStd.Persistence.Abstractions/Interfaces/Persistence/IEntityStore.cs

@@ -5,6 +5,12 @@ namespace SquidStd.Persistence.Abstractions.Interfaces.Persistence;
 /// and return detached clones; writes append to the journal then apply to memory. Reads are available
 /// in both synchronous and asynchronous forms; the async overloads delegate to the synchronous ones.
 /// </summary>
+/// <remarks>
+/// WARNING: do not register or resolve <see cref="IEntityStore{TEntity,TKey}" /> directly in the DI
+/// container - it is intentionally never registered there, and its implementation cannot be constructed
+/// by the container. Register the entity with <c>RegisterPersistedEntity</c> and obtain the store from
+/// <see cref="IPersistenceService.GetStore{TEntity,TKey}" /> instead.
+/// </remarks>
 public interface IEntityStore<TEntity, in TKey>
 {
     /// <summary>Completes synchronously from memory. Returns the number of entities of this type currently held.</summary>