v2.0.0b26

feat(scheduler): properly track SCHEDULED state for batch jobs

- Add _set_job_state_from_process() to check process state and set job
  state to SCHEDULED or RUNNING accordingly
- Add aio_wait_until_running() to Process base class with polling default
- SLURM: implement event-driven aio_wait_until_running() using watcher
- Add clock icon (🕐) for SCHEDULED state in TUI
- Show informative message when trying to view logs for SCHEDULED jobs

This enables proper tracking of jobs that are submitted to batch systems
like SLURM but not yet executing. The TUI now shows a distinct icon and
prevents attempts to view logs that don't exist yet.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>