* add tests for core functionality and client/server
* add remove subscription, get subscriptions
* fix LOTS of bugs
* add grpc tuning
* adapt to latest agreed agents_worker proto changes.

* adds a python xlang sample and aspire code to host it
* fixes message delivery on dotnet runtime

* add subscription response

* fix send subscription response

* add register agent type response

* adding a test

* working on shaping up a test

* appsettins update for backend

* another appsettings

* fixup aspire hosting

* enable AGENT_HOST var from aspire

* add SendMessageAsync

* remove broken test

* test compiles and runs but is not (yet) correct

* subscriptions grain wireup.

* temp assert true.

* remove DI for SubscriptionGrain

* add xlang python code

* add subscription response

* rebond

* Update to .NET 9.0

* Fix Backend project SDK

* Package updates

* get RegisterAgentTypeRequest working

* fix exceptions

* add error handling for requests

* whoops

* send cloud event message type

* processing cloudevents

* trying tosend proto data - doesn't work

* trying to pack proto_data

* fix (#4238)

* pack the Message from agents_events

* format - not sure why these?

* format

* cleanup, error handling, xlang sample publishes messages that can be heard by .NET and vice versa

* format

* sdk version

* sdk vers

* net8

* back to net8

* remove netstandard2

* fix used

* remove unused

* more cleanup

* remove unneeded package

* I'm terrible at writing tests

* deserialize the cloud events and sent them as events

* comment

* cleanup

* await

* Delete dotnet/samples/Hello/Backend/Backend.csproj

unneeded change

* whoops

* merge main python back into here

* revert back to local

* revert some of the helloAgents changes.

* [.NET] Add happy path test for in-memory agent && Simplify HelloAgent example && some clean-up in extension APIs (#4227)

* add happy path test

* remove unnecessary namespace

* fix build error

* Update AgentBaseTests.cs

* revert changes

---------

* fix busted merge from main

* addressing review comments

* make internal

* case sensitive rename step 1

* case sensitive rename step 2

* remove!

---------

Co-authored-by: Peter Chang <petchang@microsoft.com>
Co-authored-by: Reuben Bond <reuben.bond@gmail.com>
Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>
Co-authored-by: Xiaoyun Zhang <bigmiao.zhang@gmail.com>

* Wait for acknowledgment when sending message to gRPC channel

* Add CancellationToken parameters to API surface

* Clean up the Hello sample, support Aspire 9.0, & fix shutdown

adopts the new Microsoft.Extensions.AI abstractions
adds a base InferenceAgent
fixes a lot of pain points in the runtime wrt startup/shutdown
fixes some uncaught exceptions in the grpc stream reading
adds an example for running the backend service in its own process
adds an example of an agent that connects to OpenAI/Ollama
adds an example of wrapping an agent app in .NET Aspire
upgrades some dependencies and removes some others
Known bugs: #3922