Exclude keyed registrations from IEnumerable<T> / T[] resolution

MS DI's `IServiceProvider.GetServices(T)` and `T[]` resolution return
only non-keyed registrations; keyed registrations are looked up
explicitly via `GetKeyedService(T, key)`. Lamar's `ListInstance` /
`ArrayInstance` populated their `Elements` straight from
`ServiceGraph.FindAll`, which is built from `ServiceFamily.All` — the
flat union of keyed and non-keyed instances for a given service type.
As a result a keyed registration of `T` ended up as an `IEnumerable<T>`
element, deviating from MS DI semantics and, more importantly, causing
infinite recursion for code-generating consumers:

JasperFx's `EnumerableSingletons.KeyedMirror` registers a keyed
Singleton lambda whose factory calls `sp.GetServices(elementType)` to
return the shared non-keyed singleton instance. When Lamar inlines the
mirror's Singleton via `InjectedServiceField.ToVariableExpression`'s
`QuickResolve`, the factory invokes `sp.GetServices(T)`, Lamar resolves
the `IEnumerable<T>` family (still including the mirror itself), the
generated build frame inlines the mirror again, and so on — ~750-frame
stack overflow before any handler runs.

Filter `IsKeyedService` out of `createPlan` in both `ListInstance` and
`ArrayInstance`, matching MS DI's behaviour and breaking the cycle.
Explicit keyed lookups (`GetKeyedService(T, key)`) are unaffected.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jeremydmiller

src/Lamar/IoC/Enumerables/ArrayInstance.cs

@@ -63,7 +63,13 @@ protected override IEnumerable<Instance> createPlan(ServiceGraph services)
         }
         else
         {
-            Elements = services.FindAll(typeof(T));
+            // MS DI's IServiceProvider.GetServices(T) (and by extension T[] resolution) returns
+            // only non-keyed registrations; keyed registrations are looked up explicitly via
+            // GetKeyedService(T, key). Match that here so a keyed-mirror registration of the
+            // same service type doesn't end up as a T[] element. Otherwise inlining the
+            // mirror's Singleton via QuickResolve invokes the mirror's factory, which calls
+            // sp.GetServices(T) again and recursively re-enters codegen — stack overflow.
+            Elements = services.FindAll(typeof(T)).Where(x => !x.IsKeyedService).ToArray();
         }
 
         return Elements;

src/Lamar/IoC/Enumerables/ListInstance.cs

@@ -56,7 +56,13 @@ protected override IEnumerable<Instance> createPlan(ServiceGraph services)
         }
         else
         {
-            Elements = services.FindAll(typeof(T));
+            // MS DI's IServiceProvider.GetServices(T) returns only non-keyed registrations;
+            // keyed registrations are looked up explicitly via GetKeyedService(T, key). Match
+            // that here so a keyed-mirror registration of the same service type doesn't end up
+            // as an IEnumerable<T> element. Otherwise inlining the mirror's Singleton via
+            // QuickResolve invokes the mirror's factory, which calls sp.GetServices(T) again
+            // and recursively re-enters ListInstance/ArrayInstance code-gen — stack overflow.
+            Elements = services.FindAll(typeof(T)).Where(x => !x.IsKeyedService).ToArray();
         }
 
         return Elements;