Tighten stack overlap; fix folder top tabs; replace paper with rack.

Cards and trace use negative-margin overlap; folder tabs stay above bodies; new server-rack variant.

Co-authored-by: Cursor <cursoragent@cursor.com>

vite.config.js

@@ -12,8 +12,8 @@ export default defineConfig({
         vault: resolve(__dirname, 'vault/index.html'),
         stack: resolve(__dirname, 'stack/index.html'),
         stackFolder: resolve(__dirname, 'stack-folder/index.html'),
-        stackPaper: resolve(__dirname, 'stack-paper/index.html'),
         stackTrace: resolve(__dirname, 'stack-trace/index.html'),
+        stackRack: resolve(__dirname, 'stack-rack/index.html'),
       },
     },
   },