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/org/header.tmpl

@@ -19,7 +19,7 @@
 			</span>
 		</div>
 		{{if .RenderedDescription}}<div class="render-content markup">{{.RenderedDescription}}</div>{{end}}
-		<div class="text light meta tw-mt-1">
+		<div class="tw-text-text-light meta tw-mt-1">
 			{{if .Org.Location}}<div class="flex-text-block">{{svg "octicon-location"}} <span>{{.Org.Location}}</span></div>{{end}}
 			{{if .Org.Website}}<div class="flex-text-block">{{svg "octicon-link"}} <a class="muted" target="_blank" rel="me" href="{{.Org.Website}}">{{.Org.Website}}</a></div>{{end}}
 			{{if .IsSigned}}