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>

web_src/js/components/DiffFileTreeItem.vue

@@ -12,13 +12,13 @@ const collapsed = shallowRef(props.item.IsViewed);
 
 function getIconForDiffStatus(pType: DiffStatus) {
   const diffTypes: Record<DiffStatus, { name: SvgName, classes: Array<string> }> = {
-    '': {name: 'octicon-blocked', classes: ['text', 'red']}, // unknown case
-    'added': {name: 'octicon-diff-added', classes: ['text', 'green']},
-    'modified': {name: 'octicon-diff-modified', classes: ['text', 'yellow']},
-    'deleted': {name: 'octicon-diff-removed', classes: ['text', 'red']},
-    'renamed': {name: 'octicon-diff-renamed', classes: ['text', 'teal']},
-    'copied': {name: 'octicon-diff-renamed', classes: ['text', 'green']},
-    'typechange': {name: 'octicon-diff-modified', classes: ['text', 'green']}, // there is no octicon for copied, so renamed should be ok
+    '': {name: 'octicon-blocked', classes: ['tw-text-red']}, // unknown case
+    'added': {name: 'octicon-diff-added', classes: ['tw-text-green']},
+    'modified': {name: 'octicon-diff-modified', classes: ['tw-text-yellow']},
+    'deleted': {name: 'octicon-diff-removed', classes: ['tw-text-red']},
+    'renamed': {name: 'octicon-diff-renamed', classes: ['tw-text-teal']},
+    'copied': {name: 'octicon-diff-renamed', classes: ['tw-text-green']},
+    'typechange': {name: 'octicon-diff-modified', classes: ['tw-text-green']}, // there is no octicon for copied, so renamed should be ok
   };
   return diffTypes[pType] ?? diffTypes[''];
 }