Add !important to override global pre line-height

The global rule `pre { line-height: 1.5 !important }` in custom.css
was overriding the diagram-specific line-height. Added !important
to architectureDiagram pre rules to ensure line-height: 1 takes effect.

Author: claude

src/pages/index.module.css

@@ -75,7 +75,7 @@
   font-family: "JetBrains Mono Variable", "JetBrains Mono", "Fira Code", "Source Code Pro", monospace;
   font-size: 13px;
   font-weight: 450;
-  line-height: 1;
+  line-height: 1 !important;
   letter-spacing: 0px;
   background: transparent;
   padding: 1px;
@@ -194,7 +194,7 @@ html[data-theme="dark"] .signupSectionFullWidth {
   .architectureDiagram pre {
     font-size: 1rem;
     padding: 15px;
-    line-height: 1;
+    line-height: 1 !important;
   }
 
   .featuresGrid {