* Improve exception diagnostics for stdio client
Track the last several lines of stderr and include those in an exception created as part of CleanupAsync if the server process has already exited. This is based on an assumption that the server should never exit prior to CleanupAsync being called.
* Address feedback and fix test failure
- Changes IJsonRpcMessage to an abstract base class so RelatedTransport will always be available
- Streamable HTTP supports multiple concurrent HTTP request with their own indpendent SSE response streams
- RelatedTransport indicates the source or destination of the JsonRpcMessage
- Changes the default RequestId to a JSON number for better compatibility with MCP servers in the wild
* AI generated `///` comment updates
* Fix compilation issues
* Fix incorrect XML comment structure
* Update all Client comments
* Update all Configuration comments
* Update all Messages comments
* Update all Transport comments
* Update all Types comments
* Update all Server comments
* Undo some commenting
---------
Co-authored-by: Stephen Toub <stoub@microsoft.com>
* Reduce dependencies to 8.x versions of packages
When building for netstandard2.0 or net8.0, the ModelContextProtocol library now only depends on 8.x versions of nuget packages, rather than using the newer 9.x versions. The exception to this are packages that don't have 8.x versions.
This also introduces a net9.0 tfm. When building for net9.0, it'll use 9.x versions of packages.
The PR temporarily removes the Microsoft.Extensions.AI.nupkg reference (the Microsoft.Extensions.AI.Abstractions reference is still very much there). The latest Microsoft.Extensions.AI package on nuget has a System.Text.Json 9.x reference, but the next build to be published drops that down to 8.x as well. Once that build is published, the dependency will be added back, and temporary polyfills (in particular TemporaryAIFunctionFactory) will be deleted.
* Fix StdioClientSessionTransport shutdown
StreamClientSessionTransport's ReadMessageAsync method does await CleanupAsync in its finally. CleanupAsync awaits _readTask. _readTask _is_ ReadMessageAsync. So it's waiting for itself to complete, which will then always timeout. We may want to refactor how this works more in the future, but for now, make sure it doesn't wait for itself.
* Fix dangling requests when server unexpectedly shuts down
If the client makes a request to the server and while waiting for the response the server shuts down, the client hangs. Make sure that when the client's message loops ends due to the server's output it's reading from ends, any pending requests are notified.
* Add net9.0 testing
* Avoid docker port conflicts from test suites running concurrently
