fix(agent): dismiss tool feedback when outbound is skipped

[bogdanovich]

Summary

• dismiss tracked tool feedback when the final outbound is skipped because the tool already replied to the same chat
• add a regression test covering in that path

Testing

• go test ./pkg/agent -run 'TestPublishResponseIfNeeded_DismissesToolFeedbackWhenMessageToolAlreadySent|TestProcessMessage_PublishesToolFeedbackWhenEnabled|TestNewAgentLoop' -count=1

[bogdanovich]

Follow-up summary:

• dismiss tracked tool feedback when the final outbound is skipped because the message tool already replied to the same chat
• add a regression test covering PublishResponseIfNeeded in that path

Tested with:

• go test ./pkg/agent -run 'TestPublishResponseIfNeeded_DismissesToolFeedbackWhenMessageToolAlreadySent|TestProcessMessage_PublishesToolFeedbackWhenEnabled|TestNewAgentLoop' -count=1