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/index.ts

@@ -2,7 +2,8 @@ import '../fomantic/build/fomantic.js';
 import '../css/index.css';
 
 import {initDashboardRepoList} from './features/dashboard.ts';
-import {initGlobalCopyToClipboardListener} from './features/clipboard.ts';
+import {initGlobalCopyToClipboardListener} from './modules/clipboard.ts';
+import {initCopyContent} from './features/copycontent.ts';
 import {initRepoGraphGit} from './features/repo-graph.ts';
 import {initHeatmap} from './features/heatmap.ts';
 import {initImageDiff} from './features/imagediff.ts';
@@ -40,7 +41,6 @@ import {initRepoBranchButton} from './features/repo-branch.ts';
 import {initCommonOrganization} from './features/common-organization.ts';
 import {initRepoWikiForm} from './features/repo-wiki.ts';
 import {initRepository, initBranchSelectorTabs} from './features/repo-legacy.ts';
-import {initCopyContent} from './features/copycontent.ts';
 import {initCaptcha} from './features/captcha.ts';
 import {initRepositoryActionView} from './features/repo-actions.ts';
 import {initGlobalTooltips} from './modules/tippy.ts';