fix(agent): publish outbound media regardless of SendResponse flag

The SendResponse flag controls whether the agent loop publishes the
final text response (callers that publish it themselves set this to
false). However, the media publish path was also gated behind this
flag, which meant tool-produced media was silently dropped for normal
channel messages.

Media should be published immediately when a tool returns media refs,
independent of how the text response is delivered.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/agent/loop.go

@@ -1149,7 +1149,7 @@ func (al *AgentLoop) runLLMIteration(
 			}
 
 			// If tool returned media refs, publish them as outbound media
-			if len(r.result.Media) > 0 && opts.SendResponse {
+			if len(r.result.Media) > 0 {
 				parts := make([]bus.MediaPart, 0, len(r.result.Media))
 				for _, ref := range r.result.Media {
 					part := bus.MediaPart{Ref: ref}