Label your agent steps

This post introduces the ability to set human-readable summaries on Temporal Activities, Timers, and Workflows. For Activities, this is achieved via the `summary` option during execution. For Timers, the `summary` field can be set during `workflow.sleep`. For Workflows, `static_summary`, `static_details`, and `current_details` fields are introduced. `static_summary` and `static_details` are immutable and set at workflow start, while `current_details` is mutable and can be updated during workflow execution. These features enhance the observability of agentic workflows by providing clear labels in the Temporal UI's timeline and compact history views, making it easier to understand the state and progress of complex agentic loops and debugging sessions.