* fix(app): focus explicitly opened workspace tabs
Explicit tab navigation could be overwritten by attention-aware workspace
navigation when the visible agent had just finished. Make workspace navigation
own both normal attention selection and explicit targets so callers cannot
sequence them inconsistently.
* test(app): strengthen forked tab focus assertion
* fix(chat): keep attachments visible after creating agents
Agent creation could receive the canonical user message before the client knew the new agent ID. Hand the local rich presentation to that message and preserve it through later timeline hydration.
* refactor(chat): clarify local message presentation naming
* fix(chat): clear pending state after message handoff