[A11Y] Fix remaining small fonts in help.html

Additional fix for #702 - increased font sizes from 10-11px to 12px.

help.html

@@ -73,7 +73,7 @@
     display: inline-flex;
     align-items: center;
     gap: 6px;
-    font-size: 11px;
+    font-size: 12px;
     letter-spacing: 0.1em;
     text-transform: uppercase;
     color: var(--color-text-muted);
@@ -170,7 +170,7 @@
   kbd {
     display: inline-block;
     font-family: var(--font-body);
-    font-size: 10px;
+    font-size: 12px;
     font-weight: 600;
     letter-spacing: 0.05em;
     background: rgba(74,240,192,0.08);
@@ -286,7 +286,7 @@
     margin-top: 32px;
     padding-top: 16px;
     border-top: 1px solid var(--color-border);
-    font-size: 11px;
+    font-size: 12px;
     color: var(--color-text-muted);
     display: flex;
     align-items: center;
@@ -297,7 +297,7 @@
 
   .footer-brand {
     font-family: var(--font-display);
-    font-size: 10px;
+    font-size: 12px;
     letter-spacing: 0.12em;
     color: var(--color-primary);
     opacity: 0.7;