docs: correct the README's requirements, diagnostics, generated code and performance

Author: glennawatson

README.md

@@ -38,7 +38,8 @@ Key features:
 
 ### Requirements
 
-- .NET SDK: Any version supporting C# 7.3 or later
+- Compiler: .NET SDK 9.0.300 or later, or Visual Studio 2022 17.14 or later (the generator is built against Roslyn 4.14)
+- Language: C# 8.0 or later (the generated code uses `#nullable` directives)
 - Target Frameworks: .NET Framework 4.6.2+, .NET 8+, .NET 9+, .NET 10+
 - Splat: Version 19.1.1 or later (supports modern generic-first resolvers)
 
@@ -301,12 +302,15 @@ The package includes intelligent analyzers that provide real-time feedback:
 
 | Diagnostic ID | Severity | Description | Code Fix |
 |--------------|----------|-------------|----------|
-| SPLATDI001 | Warning | Multiple constructors without `[DependencyInjectionConstructor]` attribute | Adds attribute to selected constructor |
+| SPLATDI001 | Error | Multiple constructors without `[DependencyInjectionConstructor]` attribute | Adds attribute to selected constructor |
 | SPLATDI002 | Error | Property with `[DependencyInjectionProperty]` lacks accessible setter | Changes setter to `public` or `internal` |
 | SPLATDI003 | Error | Multiple constructors marked with `[DependencyInjectionConstructor]` | Manual fix required |
 | SPLATDI004 | Error | Constructor marked with `[DependencyInjectionConstructor]` is not accessible | Changes to `public` or `internal` |
+| SPLATDI005 | Error | Registered types depend on each other through their constructors in a cycle | Manual fix required |
+| SPLATDI006 | Warning | A service is registered more than once with the same contract | Manual fix required |
+| SPLATDI007 | Error | A constructor takes `Lazy<T>` of a service that is not registered with `RegisterLazySingleton` | Manual fix required |
 
-The analyzer detects issues in real-time and offers automatic fixes via Quick Actions (Ctrl+. or Cmd+.).
+The analyzer detects issues in real-time and offers automatic fixes via Quick Actions (Ctrl+. or Cmd+.). SPLATDI005 to SPLATDI007 need every registration in the project, so the source generator reports them when it runs.
 
 ## How It Works
 
@@ -317,37 +321,35 @@ The source generator follows a four-step process:
 3. Code Generation - Generates optimized registration code with no reflection
 4. Incremental Builds - Only regenerates when relevant code changes
 
-Generated code example:
+The code generated for the [Complete Example](#complete-example):
 
 ```csharp
-// Generated by Splat.DependencyInjection.SourceGenerator
-static partial void SetupIOCInternal(IDependencyResolver resolver)
+static partial void SetupIOCInternal(Splat.IDependencyResolver resolver)
 {
-    // Transient registration
-    resolver.Register<IUserService>(() => new UserService(
-        (IDatabase)resolver.GetService(typeof(IDatabase)),
-        (ILogger)resolver.GetService(typeof(ILogger))
-    ) {
-        Navigation = (INavigationService)resolver.GetService(typeof(INavigationService))
-    });
-
-    // Lazy singleton registration
-    {
-        var lazy = new Lazy<IDatabase>(() => new SqliteDatabase(),
-            LazyThreadSafetyMode.ExecutionAndPublication);
-        resolver.Register<Lazy<IDatabase>>(() => lazy);
-        resolver.Register<IDatabase>(() => lazy.Value);
-    }
+    resolver.Register<global::ILogger>(() => new global::FileLogger());
+
+    resolver.Register<global::IUserService>(
+        () => new global::UserService(
+            resolver.GetService<global::IDatabase>() ?? ThrowNotRegistered<global::IDatabase>("global::IDatabase"))
+        {
+            Logger = resolver.GetService<global::ILogger>() ?? ThrowNotRegistered<global::ILogger>("global::ILogger"),
+        });
+
+    var lazy0 = new global::System.Lazy<global::IDatabase>(() => new global::SqliteDatabase());
+    resolver.Register<global::System.Lazy<global::IDatabase>>(() => lazy0);
+    resolver.Register<global::IDatabase>(() => lazy0.Value);
 }
 ```
 
-## Performance Benefits
+Transient registrations are made before lazy singletons. A missing dependency throws an `InvalidOperationException` naming its type, from a `ThrowNotRegistered` helper written into the same file.
+
+## Performance
+
+- No reflection at run time: resolving a service allocates only the objects it constructs, and a registration with no dependencies creates its factory delegate once
+- Full Native AOT and trimming support
+- Builds: a generation pass over 128 registrations takes 9.6 ms and allocates 1.8 MB, and an IDE edit elsewhere in the project reruns it in 8.2 ms. An edit that only moves registrations does not regenerate the file
 
-Compared to reflection-based DI:
-- Approximately 100x faster registration execution (no runtime reflection)
-- Approximately 10-100x faster incremental builds (only processes changed files)
-- Full AOT support (works with Native AOT and trimming)
-- Zero runtime overhead (all work done at compile-time)
+The benchmarks, and how to reproduce these figures, are in [src/benchmarks/README.md](src/benchmarks/README.md).
 
 ## Troubleshooting
 
@@ -402,7 +404,7 @@ We welcome contributions! Here's how you can help:
 3. Documentation: Help improve our examples and docs
 4. Testing: Add test cases for edge scenarios
 
-See our [contribution guidelines](CONTRIBUTING.md) for details.
+See the [ReactiveUI contribution guide](https://www.reactiveui.net/contribute/index.html) for details.
 
 ## Sponsors