Desktop: surface scheduled-task final output — auto-expand submit_and_exit and render its summary as markdown (#13612)

* desktop: auto-expand submit_and_exit and render its summary as markdown

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

* desktop: render submit summary in full foreground color

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

* desktop: label the submit row 'Scheduled task completed'

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

* desktop: label errored submit_and_exit rows as failed

Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>

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Co-authored-by: Saoud Rizwan <saoudrizwan@users.noreply.github.com>