Warn and fix identity conflict when owned entity has inconsistent data in DB

[Copilot]

When a row has NULL in a non-nullable column of an outer owned entity but non-NULL values in nested inner owned entity columns, EF Core silently materializes the outer as null while still tracking the inner entity. Any subsequent SaveChanges after replacing the outer owned entity then throws a misleading InvalidOperationException about an identity conflict.

Root cause

IncludeReference only handles the case where the owner entity is non-null. When the owner is null (due to the inconsistent data), the already-tracked inner entity remains in the state manager as an orphan, causing the identity conflict later.

Changes

• IncludeReference fix (ShaperProcessingExpressionVisitor.ClientMethods.cs): Added an else if branch that detects a null owner with a non-null tracked owned entity on an ownership navigation. The caller detaches the orphaned entry (via the new QueryContext.TryGetEntry) and logs the appropriate warning.

• QueryContext.TryGetEntry(object entity) (new [EntityFrameworkInternal] method): Looks up a tracked entity by object reference in the state manager. Used by the shaper to retrieve and detach orphaned owned entities.

• CoreEventId.InconsistentOwnedDataWarning (new event, Warning level): Surfaced via CoreLoggerExtensions.InconsistentOwnedData (non-sensitive) and CoreLoggerExtensions.InconsistentOwnedDataSensitive (includes key values when sensitive data logging is enabled). Default behavior (with WarningBehavior.Throw) will throw on inconsistent data; users can configure to Log or Ignore.

• API baseline (EFCore.baseline.json): Updated for the new public members.

• Test (OwnedEntityQueryRelationalTestBase): Verifies that the warning is logged, Outer is null, and SaveChanges succeeds after replacing the owned entity with a valid instance.

// DB row: (Id=X, Outer_RequiredProperty=NULL, Outer_Inner_InnerProperty=42)
var root = await context.Set<RootEntity>().SingleAsync();
// root.Outer == null  ← was silently null before; now logs InconsistentOwnedDataWarning

root.Outer = new Outer { RequiredProperty = 1, Inner = new Inner { InnerProperty = 2 } };
await context.SaveChangesAsync(); // ← previously threw InvalidOperationException (identity conflict)