feat: update SEO handling by dynamically setting canonical links and exclude auth pages from sitemap

frontend/index.html

@@ -13,7 +13,7 @@
     <meta name="keywords" content="arduino emulator, arduino simulator, arduino simulator free, avr8 emulator, avr simulator, atmega328p simulator, atmega2560 simulator, attiny85 simulator, arduino uno simulator, arduino mega simulator, arduino nano simulator, rp2040 emulator, raspberry pi pico simulator, esp32 emulator, esp32 simulator, esp32-c3 simulator, esp32-s3 emulator, risc-v simulator, ch32v003, raspberry pi 3 emulator, wokwi alternative, arduino ide browser, arduino online, electronics simulator, velxio" />
     <meta name="author" content="David Montero Crespo" />
     <meta name="robots" content="index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1" />
-    <link rel="canonical" href="https://velxio.dev/" />
+    <!-- canonical is set dynamically per-route by the useSEO hook -->
 
     <!-- Google Search Console verification — replace token after verifying in Search Console -->
     <!-- <meta name="google-site-verification" content="REPLACE_WITH_YOUR_VERIFICATION_TOKEN" /> -->

frontend/public/sitemap.xml

@@ -129,18 +129,6 @@
     <priority>0.85</priority>
   </url>
 
-  <url>
+  <!-- Auth pages intentionally excluded from sitemap (not for indexing) -->
-    <loc>https://velxio.dev/login</loc>
-    <lastmod>2026-03-06</lastmod>
-    <changefreq>yearly</changefreq>
-    <priority>0.3</priority>
-  </url>
-
-  <url>
-    <loc>https://velxio.dev/register</loc>
-    <lastmod>2026-03-06</lastmod>
-    <changefreq>yearly</changefreq>
-    <priority>0.3</priority>
-  </url>
 
 </urlset>

frontend/src/utils/useSEO.ts

@@ -47,6 +47,17 @@ export function useSEO({ title, description, url, ogImage, jsonLd }: SEOMeta) {
     const origTwDesc    = get(twDescEl);
     const origCanonical = canonicalEl?.getAttribute('href') ?? '';
 
+    // If no <link rel="canonical"> exists yet, create one so each SPA route
+    // gets its own canonical (avoids all routes appearing to point back to /).
+    let createdCanonical = false;
+    let activeCanonical: HTMLLinkElement | null = canonicalEl as HTMLLinkElement | null;
+    if (!activeCanonical) {
+      activeCanonical = document.createElement('link') as HTMLLinkElement;
+      activeCanonical.rel = 'canonical';
+      document.head.appendChild(activeCanonical);
+      createdCanonical = true;
+    }
+
     // Apply
     document.title = title;
     set(descEl, description);
@@ -56,7 +67,7 @@ export function useSEO({ title, description, url, ogImage, jsonLd }: SEOMeta) {
     if (ogImage) set(ogImgEl, ogImage);
     set(twTitleEl, title);
     set(twDescEl, description);
-    canonicalEl?.setAttribute('href', url);
+    activeCanonical.setAttribute('href', url);
 
     // Inject JSON-LD once (module-level constants don't change)
     if (jsonLd && !scriptRef.current) {
@@ -77,7 +88,11 @@ export function useSEO({ title, description, url, ogImage, jsonLd }: SEOMeta) {
       if (ogImage) set(ogImgEl, origOgImg);
       set(twTitleEl, origTwTitle);
       set(twDescEl, origTwDesc);
-      canonicalEl?.setAttribute('href', origCanonical);
+      if (createdCanonical && activeCanonical && document.head.contains(activeCanonical)) {
+        document.head.removeChild(activeCanonical);
+      } else {
+        activeCanonical?.setAttribute('href', origCanonical);
+      }
       if (scriptRef.current) {
         document.head.removeChild(scriptRef.current);
         scriptRef.current = null;