style: enforce 12px minimum font size across all components

Add --font-size-min: 12px token to tokens.css. Replace all 10px and 11px
font-size declarations with 12px across 54 CSS module files for improved
readability.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/pages/Admin/UserManagement/UserManagement.module.css

@@ -11,7 +11,7 @@
 }
 
 .entityMeta {
-  font-size: 11px;
+  font-size: 12px;
   color: var(--text-muted);
   font-family: var(--font-body);
   margin-top: 2px;
@@ -101,7 +101,7 @@
 }
 
 .inheritedNote {
-  font-size: 11px;
+  font-size: 12px;
   color: var(--text-muted);
   font-style: italic;
   font-family: var(--font-body);