fix(ui): prevent commit status popup overflowing its row (#38081)

Fixes #38079

## Regression path

The layout previously had `.commit-status-item .status-context { flex: 1
}`,
which let the context fill remaining space and ellipsize. That rule was
dropped in #37517 ("Refactor pull request view (5)") when the row markup
moved to nested `.flex-text-block` wrappers, so nothing constrained the
left block anymore.

After:
<img width="832" height="242" alt="image"
src="https://github.com/user-attachments/assets/a20019f8-6016-40f7-8901-2808280dc093"
/>

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/pulls/status_items.tmpl

@@ -6,14 +6,14 @@
 {{$commitActionsStatuses :=  ctx.ActionsUtils.CommitStatusesToActionsStatuses $.CommitStatuses}}
 {{range $cs := $.CommitStatuses}}
 	<div class="item commit-status-item">
-		<div class="flex-text-block">
+		<div class="flex-text-block tw-flex-1">
 			{{$actionStatus := $commitActionsStatuses.IconStatus $cs}}
 			{{if $actionStatus}}
 				{{template "repo/icons/action_status" (dict "Status" $actionStatus "Size" 18 "ClassName" "commit-status icon")}}
 			{{else}}
 				{{template "repo/icons/commit_status" $cs}}
 			{{end}}
-			<div class="status-context gt-ellipsis">
+			<div class="gt-ellipsis">
 				{{$cs.Context}} <span class="tw-text-text-light-2">{{$cs.Description}}</span>
 			</div>
 		</div>
@@ -29,9 +29,9 @@
 {{end}}
 {{range $missingCheck := $statusCheckData.MissingRequiredChecks}}
 	<div class="item commit-status-item">
-		<div class="flex-text-block">
+		<div class="flex-text-block tw-flex-1">
 			{{svg "octicon-dot-fill" 16 "commit-status icon tw-text-yellow"}}
-			<div class="status-context gt-ellipsis">{{$missingCheck}}</div>
+			<div class="gt-ellipsis">{{$missingCheck}}</div>
 		</div>
 		<div class="ui label">{{ctx.Locale.Tr "repo.pulls.status_checks_requested"}}</div>
 	</div>