* 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
changes to AgentBase and HostBuilderExtensions to enable leveraging handlers from composition (interfaces) vs inheritance... see HelloAgents sample for usage
closes#3928
is related to #3925
Remove unused code, refactor AgentBase and AgentWorker/Runtime to use interfaces throughout to enable future implementation of alternate runtimes and separation of the gprpc service from Agent Base (for future in-memory version).
Also adds the missing RegisterAgentResponse methods
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
* add service defaults to Host
* add otel to app host
* ran format
* remove HelloAgents
* moving things around to fit the folder structure/naming conventions
---------
Co-authored-by: Xiaoyun Zhang <bigmiao.zhang@gmail.com>
