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/Inventory/sections/LayoutSection.module.css

@@ -56,7 +56,7 @@
 }
 
 .demoLabel {
-  font-size: 11px;
+  font-size: 12px;
   color: var(--text-muted);
   font-weight: 500;
 }
@@ -80,7 +80,7 @@
   border: 1px solid var(--border);
   border-radius: var(--radius-sm);
   overflow: hidden;
-  font-size: 11px;
+  font-size: 12px;
   color: var(--text-muted);
 }