* Incremental work on Telnyx integration
* Incremental port of Telnyx activities
* Fix polymorphic JSON serialization for webhook data
* Fix IsFirstPass logic
* Fix trigger base to prevent activity auto completion
* Temporarily disable persistent snapshotting provider for testing
* Fix namespaces
* Add method to register activities in bulk using marker type
* Fix Telnyx refit client setup
* Register all Telnyx activities by default
* Incremental work on webhook driven resumption and correlation
* Incremental work on post-bookmark signaling
* Fix bookmark resolution
* Include correlation ID with bookmark
* Fix Telnyx resumption input
* Replace bookmark persisted signal with handler
* Fix SpeakText completion
* Add flow outcomes to SpeakText activity
* Update GatherUsingSpeak and GatherUsingaudio
* Refactor "is first pass" concept
* Fix WebhookEvent activity
* Add HTTP absolute URL provider
* Formatting and small changes
* Various API enhancements
* Initial working grain
* Incremental work on actor bookmark management & resuming wokflows
* Upgrade Proto Actor package references
* Fix lifetime of actors
* Implement bookmark and resumption
* Update Program.cs
* Update bookmark event publishing
* Refactor proto actor features API
* Implement snapshotting
* Update snapshotting
* Add in-memory provider and use it by default
* Update server bundle to use proto actor sqlite persistence by default