Refactor text utility classes to Tailwind CSS (#36703)

Replace Fomantic/custom CSS text utility classes with their Tailwind
equivalents:

- `.text.<color>` compound classes → `tw-text-<color>` classes
- `.text.small` (`font-size: 0.75em`) → `tw-text-xs` (11px)
- `.text.truncate` (`overflow-x: hidden; text-overflow: ellipsis;
white-space: nowrap; display: inline-block`) → `tw-inline-block
tw-truncate`

Remove the now-unused CSS rules from `base.css` and `dashboard.css`.

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

templates/repo/pulls/status.tmpl

@@ -40,7 +40,7 @@
 		{{range .CommitStatuses}}
 			<div class="commit-status-item">
 				{{template "repo/commit_status" .}}
-				<div class="status-context gt-ellipsis">{{.Context}} <span class="text light-2">{{.Description}}</span></div>
+				<div class="status-context gt-ellipsis">{{.Context}} <span class="tw-text-text-light-2">{{.Description}}</span></div>
 				<div class="ui status-details">
 					{{if and $statusCheckData $statusCheckData.IsContextRequired}}
 						{{if (call $statusCheckData.IsContextRequired .Context)}}<div class="ui label">{{ctx.Locale.Tr "repo.pulls.status_checks_requested"}}</div>{{end}}
@@ -52,7 +52,7 @@
 		{{if $statusCheckData}}
 			{{range $statusCheckData.MissingRequiredChecks}}
 				<div class="commit-status-item">
-					{{svg "octicon-dot-fill" 18 "commit-status icon text yellow"}}
+					{{svg "octicon-dot-fill" 18 "commit-status icon tw-text-yellow"}}
 					<div class="status-context gt-ellipsis">{{.}}</div>
 					<div class="ui label">{{ctx.Locale.Tr "repo.pulls.status_checks_requested"}}</div>
 				</div>