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/modules/codeeditor/context-menu.ts

@@ -1,5 +1,5 @@
-import {clippie} from 'clippie';
 import {createTippy} from '../tippy.ts';
+import {copyToClipboard} from '../clipboard.ts';
 import {keySymbols} from '../../utils.ts';
 import {goToDefinitionAt} from './utils.ts';
 import type {Instance} from 'tippy.js';
@@ -95,13 +95,13 @@ function buildMenuItems(cm: CodemirrorModules, view: EditorView, togglePalette:
     'separator',
     {label: 'Cut', keys: 'Mod+X', disabled: !hasSelection, run: async (v) => {
       const {from, to} = v.state.selection.main;
-      if (await clippie(v.state.doc.sliceString(from, to))) {
+      if (await copyToClipboard(v.state.doc.sliceString(from, to))) {
         v.dispatch({changes: {from, to}});
       }
     }},
     {label: 'Copy', keys: 'Mod+C', disabled: !hasSelection, run: async (v) => {
       const {from, to} = v.state.selection.main;
-      await clippie(v.state.doc.sliceString(from, to));
+      await copyToClipboard(v.state.doc.sliceString(from, to));
     }},
     {label: 'Paste', keys: 'Mod+V', run: async (view) => {
       try {