enhance(actions): Make Summary UI more beautiful with more infos (#37824)

## Summary

- Redesign the Actions run summary header to follow GitHub Actions
layout: trigger info on the left, Status / Total duration / Artifacts
columns inline on the right
- Expose trigger user avatar, pull request link, and PR head branch info
from the run view API
- Update the workflow graph header to show the workflow filename (linked
to the run workflow file) and `on: <event>`, while keeping the
jobs/dependencies/success stats line
- Remove the redundant commit/workflow metadata row below the run title;
that information now lives in the summary bar

New:
<img width="1564" height="639"
src="https://github.com/user-attachments/assets/e6bc1623-c5fc-4e97-abc9-fde7f3c6aef9"
/>

Old:
<img width="2038" height="1038"
src="https://github.com/user-attachments/assets/0857f19a-8d3a-4da2-82fd-e9ebeb200062"
/>

Replaces https://github.com/go-gitea/gitea/pull/36721

---------

Co-authored-by: Giteabot <teabot@gitea.io>

web_src/js/components/ActionRunView.ts

@@ -126,6 +126,7 @@ export function createEmptyActionsRun(): ActionsRun {
     duration: '',
     triggeredAt: 0,
     triggerEvent: '',
+    pullRequest: null,
     jobs: [] as Array<ActionsJob>,
     commit: {
       localeCommit: '',
@@ -135,6 +136,7 @@ export function createEmptyActionsRun(): ActionsRun {
       pusher: {
         displayName: '',
         link: '',
+        avatarLink: '',
       },
       branch: {
         name: '',