feat: add copy button to action step header, improve other copy buttons (#37744)

- Adds a copy button to each action step header that copies the step's
rendered log output to clipboard.
- Extract a shared `copyToClipboard(target, content)` helper in
`clipboard.ts` that adds SVG success/failure feedback.
- `is-loading` height for the new helper is sourced from
`--loading-size`.
- Change actions log timestamp format to include seconds.

The indented-markdown code-block fix has moved to #37748.

<img width="244" height="165" alt="copystep"
src="https://github.com/user-attachments/assets/ce286b51-f77b-4d82-b161-ca0aa7ec4fdc"
/>

<img width="187" height="150" alt="copybt"
src="https://github.com/user-attachments/assets/5366b290-b776-496d-8dd4-58d5fa60be92"
/>

Fixes: https://github.com/go-gitea/gitea/issues/26116

---
This PR was written with the help of Claude Opus 4.7

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Nicolas <bircni@icloud.com>

web_src/js/features/repo-code.ts

@@ -41,9 +41,8 @@ function selectRange(range: string): Element | null {
   const updateCopyPermalinkUrl = function (anchor: string) {
     if (!copyPermalink) return;
     let link = copyPermalink.getAttribute('data-url')!;
-    link = `${link.replace(/#L\d+$|#L\d+-L\d+$/, '')}#${anchor}`;
+    link = `${window.location.origin}${link.replace(/#L\d+$|#L\d+-L\d+$/, '')}#${anchor}`;
     copyPermalink.setAttribute('data-clipboard-text', link);
-    copyPermalink.setAttribute('data-clipboard-text-type', 'url');
   };
 
   const rangeFields = range ? range.split('-') : [];