agent: add what created a dispatch

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: boks1971

.changeset/agent-job-timing-state.md

@@ -3,4 +3,4 @@
 "@livekit/protocol": patch
 ---
 
-Add `Job.created_at`, `JobState.accepted_at` and `JobState.assigned_at`
+Add `Job.created_at`, `JobState.accepted_at`, `JobState.assigned_at` and `AgentDispatchState.trigger`

livekit/livekit_agent_dispatch.pb.go

@@ -99,5 +99,17 @@ message AgentDispatchState {
   repeated Job jobs = 1;
   int64 created_at = 2;
   int64 deleted_at = 3;
+  AgentDispatchTrigger trigger = 4;
+}
+
+// what created the dispatch
+enum AgentDispatchTrigger {
+  ADT_UNSPECIFIED = 0;
+  // a participant joining created the room, and with it the dispatch
+  ADT_JOIN = 1;
+  // the CreateRoom API created the room, and with it the dispatch
+  ADT_ROOM_API = 2;
+  // the CreateDispatch API
+  ADT_DISPATCH_API = 3;
 }