Fix line gaps in ASCII diagrams

Set line-height to 1.0 for diagram code blocks to eliminate gaps
between lines, ensuring proper vertical alignment of ASCII art
characters. This affects:
- Markdown diagram code blocks (language-diagram)
- Homepage architecture diagram on mobile

Regular code snippets retain line-height: 1.5 for better readability.

Author: claude

src/css/custom.css

@@ -30,10 +30,10 @@ pre, pre code, .prism-code {
   line-height: 1.5 !important;
 }
 
-/* ASCII diagrams: tighter line height */
+/* ASCII diagrams: no line gaps for proper character alignment */
 pre[class*="language-diagram"],
 pre[class*="language-diagram"] code {
-  line-height: 1.2 !important;
+  line-height: 1.0 !important;
 }
 
 .docusaurus-highlight-code-line {

src/pages/index.module.css

@@ -194,7 +194,7 @@ html[data-theme="dark"] .signupSectionFullWidth {
   .architectureDiagram pre {
     font-size: 1rem;
     padding: 15px;
-    line-height: 1.3;
+    line-height: 1;
   }
 
   .featuresGrid {