feat: PIXELIUM ASCII art signature in footer — subtle, low opacity

Block art at 0.12 opacity in accent blue, above footer content.
Artisan signature — rewards those who scroll to the bottom.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ferr079

src/components/Footer.astro

@@ -20,6 +20,12 @@ const t = text[lang];
 ---
 
 <footer class="site-footer">
+  <pre class="footer-ascii" aria-hidden="true"> ██████╗ ██╗██╗  ██╗███████╗██╗     ██╗██╗   ██╗███╗   ███╗
+ ██╔══██╗██║╚██╗██╔╝██╔════╝██║     ██║██║   ██║████╗ ████║
+ ██████╔╝██║ ╚███╔╝ █████╗  ██║     ██║██║   ██║██╔████╔██║
+ ██╔═══╝ ██║ ██╔██╗ ██╔══╝  ██║     ██║██║   ██║██║╚██╔╝██║
+ ██║     ██║██╔╝ ██╗███████╗███████╗██║╚██████╔╝██║ ╚═╝ ██║
+ ╚═╝     ╚═╝╚═╝  ╚═╝╚══════╝╚══════╝╚═╝ ╚═════╝ ╚═╝     ╚═╝</pre>
   <div class="footer-container">
     <div class="footer-links">
       <a href="https://github.com/ferr079" target="_blank" rel="noopener" aria-label="GitHub">
@@ -53,6 +59,19 @@ const t = text[lang];
 </script>
 
 <style>
+  .footer-ascii {
+    display: block;
+    text-align: center;
+    font-family: var(--font-mono);
+    font-size: 0.45rem;
+    line-height: 1.1;
+    color: var(--color-accent);
+    opacity: 0.12;
+    margin: 0 auto 1.5rem;
+    user-select: none;
+    overflow: hidden;
+  }
+
   .site-footer {
     padding: 2rem 0;
     border-top: 1px solid var(--color-border);