Fix language switcher to maintain clean URLs and dynamic logo links

Changes:
- Logo and title links now start with clean URLs (href="/")
- Track if URL originally had lang parameter (urlHadLangParam variable)
- If URL had lang param: update URL when switching languages, update logo/title links dynamically
- If URL was clean: keep it clean, don't add lang to URL, keep logo/title links clean
- Logo/title links now update dynamically when language changes (no more stale language issue)
- Initialize logo/title links properly on page load based on URL state

This fixes both issues:
1. Logo clicking with wrong language after language switch
2. Clean URLs stay clean unless explicitly using ?lang= parameter

templates/index.html

@@ -99,7 +99,7 @@
         <div class="action-bar-content">
             <!-- Left: Site Title + Hamburger Menu + Language -->
             <div class="site-title">
-                <a href="/?lang={{.Lang}}" class="site-logo-link" aria-label="Home">
+                <a href="/" class="site-logo-link" id="logoLink" aria-label="Home">
                     <iconify-icon icon="mdi:file-account" width="24" height="24" class="site-icon"></iconify-icon>
                 </a>
 
@@ -108,7 +108,7 @@
                     <iconify-icon icon="mdi:menu" width="24" height="24"></iconify-icon>
                 </button>
 
-                <a href="/?lang={{.Lang}}" class="site-title-link">
+                <a href="/" class="site-title-link" id="titleLink">
                     <span class="site-title-text">CV JAMR - {{.CurrentYear}}</span>
                 </a>
 
@@ -375,6 +375,9 @@
             }
         });
 
+        // Track if URL originally had lang parameter
+        const urlHadLangParam = new URLSearchParams(window.location.search).has('lang');
+
         function selectLanguage(lang) {
             // Update button states
             document.querySelectorAll('.language-selector .selector-btn').forEach(btn => {
@@ -389,10 +392,20 @@
                 indicator: '#loading'
             });
 
-            // Update URL
+            // Update URL only if it originally had lang parameter
             const url = new URL(window.location);
-            url.searchParams.set('lang', lang);
-            window.history.pushState({}, '', url);
+            if (urlHadLangParam) {
+                url.searchParams.set('lang', lang);
+                window.history.pushState({}, '', url);
+
+                // Update logo and title links to include current language
+                document.getElementById('logoLink').href = `/?lang=${lang}`;
+                document.getElementById('titleLink').href = `/?lang=${lang}`;
+            } else {
+                // Keep URL clean, but update logo/title links to stay clean too
+                document.getElementById('logoLink').href = '/';
+                document.getElementById('titleLink').href = '/';
+            }
 
             // Update html lang attribute
             document.documentElement.lang = lang;
@@ -480,6 +493,13 @@
         document.addEventListener('DOMContentLoaded', function() {
             const paper = document.querySelector('.cv-paper');
 
+            // Initialize logo/title links based on whether URL has lang parameter
+            if (urlHadLangParam) {
+                const currentLang = new URLSearchParams(window.location.search).get('lang') || 'en';
+                document.getElementById('logoLink').href = `/?lang=${currentLang}`;
+                document.getElementById('titleLink').href = `/?lang=${currentLang}`;
+            }
+
             // Restore CV length preference
             const savedLength = localStorage.getItem('cv-length') || 'short';
             if (savedLength === 'long') {