Routine header UI enhancements: download button + collapsed report history

[fengtality]

Summary

Two improvements to the routine header (where prior report runs are listed):

1. Add a download button to the header so users can export the currently selected report directly.
2. Collapse report history when > 5 entries. Today the header lists every run inline (e.g. 1m ago, 15h ago, 15h ago, ...). When there are more than 5 reports, show the first 5 inline and move the rest into a dropdown. Items in the dropdown should use an absolute date / time format (not relative "Xh ago") so older runs are easier to identify.

Reference

Current state of the header on a routine with many runs:

(Header shows 1 of 12 runs but lists all 12 inline as 1m ago / 15h ago / ... — the proposed change keeps the 5 most recent inline and moves the rest into a date/time dropdown.)

Acceptance criteria

• Download button visible in routine header next to the existing actions (Source / Config / Run / Schedule / Run All / etc.)
• Download exports the currently selected report (format TBD — likely the same artifact already viewable in the panel).
• When report count ≤ 5: render all runs inline as today.
• When report count > 5: render 5 most recent inline; remaining runs go into a dropdown.
• Dropdown entries display absolute date/time (e.g. 2026-05-27 09:35) instead of relative time.