fix(compaction): address the round-3 review of the compaction stack

agent/agent.go

@@ -238,6 +238,19 @@ func getAuthorForEvent(ctx Context, event *session.Event) string {
 	return ctx.Agent().Name()
 }
 
+// eventActionsFrom returns the actions a callback accumulated, less the fields
+// that are the framework's to write rather than a callback's.
+//
+// A callback is handed the live [session.EventActions] so it can request state
+// deltas, escalation and transfers, and the struct is then copied wholesale onto
+// the persisted event. Anything on it that changes how later prompts are built
+// has to be filtered out here, or the callback gets to set it.
+func eventActionsFrom(actions *session.EventActions) session.EventActions {
+	out := *actions
+	out.Compaction = nil
+	return out
+}
+
 // runBeforeAgentCallbacks checks if any beforeAgentCallback returns non-nil content
 // then it skips agent run and returns callback result.
 func runBeforeAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
@@ -259,7 +272,7 @@ func runBeforeAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 			}
 			event.Author = agent.Name()
 			event.Branch = ctx.Branch()
-			event.Actions = *actions
+			event.Actions = eventActionsFrom(actions)
 			ctx.EndInvocation()
 			return event, nil
 		}
@@ -280,7 +293,7 @@ func runBeforeAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 		}
 		event.Author = agent.Name()
 		event.Branch = ctx.Branch()
-		event.Actions = *actions
+		event.Actions = eventActionsFrom(actions)
 		ctx.EndInvocation()
 		return event, nil
 	}
@@ -290,7 +303,7 @@ func runBeforeAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 		event := session.NewEvent(ctx, ctx.InvocationID())
 		event.Author = agent.Name()
 		event.Branch = ctx.Branch()
-		event.Actions = *actions
+		event.Actions = eventActionsFrom(actions)
 		return event, nil
 	}
 
@@ -318,7 +331,7 @@ func runAfterAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 			}
 			event.Author = agent.Name()
 			event.Branch = ctx.Branch()
-			event.Actions = *actions
+			event.Actions = eventActionsFrom(actions)
 			return event, nil
 		}
 	}
@@ -338,7 +351,7 @@ func runAfterAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 		}
 		event.Author = agent.Name()
 		event.Branch = ctx.Branch()
-		event.Actions = *actions
+		event.Actions = eventActionsFrom(actions)
 		// TODO set context invocation ended
 		// ctx.invocationEnded = true
 		return event, nil
@@ -349,7 +362,7 @@ func runAfterAgentCallbacks(ctx InvocationContext) (*session.Event, error) {
 		event := session.NewEvent(ctx, ctx.InvocationID())
 		event.Author = agent.Name()
 		event.Branch = ctx.Branch()
-		event.Actions = *actions
+		event.Actions = eventActionsFrom(actions)
 		return event, nil
 	}
 	return nil, nil

agent/llmagent/llm_agent_wrapper.go

@@ -757,3 +757,10 @@ func (w *wrappedEvents) At(i int) *session.Event {
 		return nil
 	}
 }
+
+// Unwrap returns the session this one decorates.
+//
+// The seed a wrappedSession adds is a prompt-assembly convenience, not durable
+// conversation. Anything that has to write to the session, or reason about what
+// is actually stored, needs the session underneath.
+func (w *wrappedSession) Unwrap() session.Session { return w.Session }