Update AG-UI .NET SDK docs

docs/sdk/dotnet/abstractions/overview.mdx

@@ -23,6 +23,39 @@ event stream and request payload.
   types are registered in the source-generated `AGUIJsonSerializerContext`.
 </Note>
 
+## SDK packages
+
+The .NET SDK is split into small packages so protocol types, wire formats,
+client code, and server code can be adopted independently.
+
+| Package | Use it for |
+| --- | --- |
+| `AGUI.Abstractions` | Protocol events, messages, tools, capabilities, interrupts, and JSON serialization. |
+| `AGUI.Formatting` | Event-stream formatter abstractions and Server-Sent Events support. |
+| `AGUI.Protobuf` | Protobuf event-stream formatting and binary protocol support. |
+| `AGUI.Client` | HTTP client and `IChatClient` implementation for consuming AG-UI endpoints. |
+| `AGUI.Server` | Framework-agnostic adapter from `ChatResponseUpdate` streams to AG-UI events. |
+
+## Wire formats and parity
+
+JSON over Server-Sent Events is the full-fidelity event stream.
+`AGUI.Formatting` defines the event-stream formatter contract and SSE support.
+`AGUI.Protobuf` adds binary event-stream formatting for the protocol subset
+supported by the shared proto schema.
+
+Protocol parity starts in `AGUI.Abstractions`. When the TypeScript reference SDK
+adds or changes a wire type, the matching .NET event, message, tool, or
+capability type should update alongside `AGUIJsonSerializerContext` and the
+compatibility fixtures. Public API tracking files should update whenever a
+protocol change adds or changes .NET types.
+
+```bash
+cd sdks/dotnet
+dotnet test tests/AGUI.Abstractions.UnitTests/
+dotnet test tests/AGUI.Formatting.UnitTests/
+dotnet test tests/AGUI.Protobuf.UnitTests/
+```
+
 ## Types
 
 Core data structures that represent the building blocks of the protocol:
@@ -87,4 +120,3 @@ Events power communication between agents and frontends:
 >
   Complete documentation of all event types in `AGUI.Abstractions`
 </Card>
-

docs/sdk/dotnet/client/overview.mdx

@@ -80,3 +80,22 @@ event and as `AdditionalProperties["agui_thread_id"]`.
 
 For the protocol types carried over the wire, see the
 [.NET event reference](/sdk/dotnet/abstractions/events).
+
+## Client verification
+
+Client tests protect the conversion between `Microsoft.Extensions.AI` and
+AG-UI. They verify that `ChatMessage` history becomes AG-UI messages,
+`ChatOptions.Tools` becomes AG-UI tools, caller-supplied AG-UI context,
+forwarded properties, and resume payloads are preserved, and `RUN_ERROR`
+events become MEAI `ErrorContent` updates.
+
+They also protect the stateless conversation contract: thread and run
+identifiers are preserved through AG-UI fields, returned updates clear
+`ConversationId`, and server-side tool calls are marked informational so the
+.NET client does not execute them locally.
+
+```bash
+cd sdks/dotnet
+dotnet test tests/AGUI.Client.UnitTests/
+dotnet test tests/AGUI.CrossLanguage.IntegrationTests/
+```

docs/sdk/dotnet/hosting/overview.mdx

@@ -45,14 +45,37 @@ independent.
 The hosting layer handles the protocol details for you:
 
 - Converts `RunAgentInput.Messages` into `ChatMessage` values
+- Translates `RunAgentInput.Resume` into MEAI approval and interrupt response
+  content
 - Installs client-declared tools on `ChatOptions`
 - Stores the original input under
   `ChatOptions.AdditionalProperties[AGUIConstants.RunAgentInputKey]`
-- Emits `RUN_STARTED` and `RUN_FINISHED`
+- Emits `RUN_STARTED` and terminal `RUN_FINISHED` outcomes
 - Maps text, reasoning, tool calls, tool results, state, raw events, and
   interrupts to AG-UI events
 - Streams the result as Server-Sent Events
 
+## Verification and framework ownership
+
+Server tests verify that `RunAgentInput` becomes `ChatMessage` and
+`ChatOptions`, resume payloads become standard MEAI response content, lifecycle
+events are emitted, and streamed `ChatResponseUpdate` values become the
+expected text, reasoning, tool, state, raw, custom, and interrupt events. Raw
+AG-UI events, including `RUN_ERROR`, pass through when supplied on
+`ChatResponseUpdate.RawRepresentation`.
+
+```bash
+cd sdks/dotnet
+dotnet test tests/AGUI.Server.UnitTests/
+dotnet test tests/AGUI.Hosting.AspNetCore.IntegrationTests/
+```
+
+The SDK owns the shared AG-UI and `Microsoft.Extensions.AI` bridge.
+Framework-specific mappings belong to the consuming framework. For example,
+Microsoft Agent Framework can use `AGUI.Server` for the common bridge, then map
+its own workflow, step, and agent events with `AGUIStreamOptions` or raw AG-UI
+events.
+
 ## Server and client together
 
 Use `AGUI.Server` when you are building an AG-UI server. Use