* refactor: Normalize Run/RunStreaming with AIAgent
* refactor: Clarify Session vs. Run -level concepts
* Rename RunId to SessionId to better match Run/Session terminology in AIAgent
* [BREAKING]: Will break existing checkpointed sessions in CosmosDb due to field rename
* refactor: Rename and simplify interface around getting typed data out of ExternalRequest/Response
* Also adds hints around using value types in PortableValue
* refactor: Rename AddFanInEdge to AddFanInBarrierEdge
This will prevent a breaking change later when we introduce a programmable FanIn edge, analogous to the FanOut edge's EdgeSelector.
The goal, in the long run is to support a number of different FanIn scenarios, with naive FanIn (no barrier) by default, similar to FanOut.
* refactor: AsAgent(this Workflow, ...) => AsAIAgent(...)
* misc - part1: SwitchBuilder internal
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Co-authored-by: Dmytro Struk <13853051+dmytrostruk@users.noreply.github.com>