feat(ui): add copy button to workflow logs viewer. Fixes #636, #6384

[nakatani-yo]

Fixes #636
Fixes #6384

Motivation

When viewing workflow logs in the UI, copying log content is unnecessarily difficult. Users must manually select text in the log viewer, which is error-prone — especially for running pods where the selection gets immediately cleared as new logs stream in (#6384). This has been a long-standing UX pain point since 2018 (#636).

Modifications

• Added a "Copy" button to the workflow logs viewer toolbar that copies the entire log content to the clipboard.
• The button provides visual feedback by briefly showing a checkmark icon and "Copied" text after a successful copy.
• Internally, log lines are accumulated in a useRef so clipboard copy can access the full log content without triggering re-renders.
• Added 'clipboard' to the shared icon type definitions.

Verification

• Opened the workflow logs viewer in the browser and confirmed the Copy button appears in the toolbar.
• Clicked the button and verified log content is copied to clipboard correctly.
• Confirmed the button shows "Copied" feedback for 2 seconds before reverting.
• Verified existing log viewer functionality (streaming, filtering, download) is unaffected.

Documentation

No documentation update needed. The copy button is self-discoverable in the UI toolbar alongside existing buttons (Download, Log Fields).

AI

Codex