Enhance calculators and SEO features, improve category handling, and update metadata for better indexing

hdyc-svelte/src/lib/components/Sidebar.svelte

@@ -148,7 +148,9 @@
     if ('addEventListener' in navBreakpoint) {
       navBreakpoint.addEventListener('change', handleNavChange);
     } else {
-      navBreakpoint.addListener(handleNavChange);
+      (navBreakpoint as MediaQueryList & {
+        addListener: (listener: (event: MediaQueryListEvent) => void) => void;
+      }).addListener(handleNavChange);
     }
 
     return () => {
@@ -156,7 +158,9 @@
       if ('removeEventListener' in navBreakpoint) {
         navBreakpoint.removeEventListener('change', handleNavChange);
       } else {
-        navBreakpoint.removeListener(handleNavChange);
+        (navBreakpoint as MediaQueryList & {
+          removeListener: (listener: (event: MediaQueryListEvent) => void) => void;
+        }).removeListener(handleNavChange);
       }
     };
   });