fix: References section link corruption and download filename issues

**Issue 1: URL corruption in "See this CV in..." links**
- Bug: replaceYearPlaceholder used fmt.Sprintf on ALL URLs
- URLs like "/?lang=es" were corrupted to "/?lang=es%!(EXTRA string=2025)"
- Fix: Changed to strings.ReplaceAll("{{YEAR}}", year)
- Result: Only replaces actual {{YEAR}} placeholders, leaves other URLs intact

**Issue 2: Download filename not respected**
- Bug: Shortcut URLs (cv-jamr-2025-en.pdf) redirected with HTTP 301
- Browsers used original URL filename instead of Content-Disposition header
- Fix: Generate PDF directly in DefaultCVShortcut handler
- Result: Returns PDF with correct filename in Content-Disposition header

Files changed:
- internal/models/cv.go: Fixed replaceYearPlaceholder function
- internal/handlers/cv.go: Changed redirect to direct PDF generation

Both fixes verified:
- "See this CV in Spanish" link: href="/?lang=es" ✓
- Download link: filename=cv-jamr-2025-en.pdf ✓

templates/partials/modals/pdf-modal.html

@@ -301,10 +301,11 @@
                 formatName = isSpanish ? 'CV Actual' : 'Current CV';
             }
 
-            // Show loading overlay
+            // Show loading overlay in modal
             const overlay = document.getElementById('pdf-loading-overlay');
             const modalContent = document.getElementById('pdf-modal-content');
             const estimateEl = document.getElementById('pdf-loading-estimate');
+            const modal = document.getElementById('pdf-modal');
 
             overlay.classList.add('active');
             modalContent.classList.add('loading-active');
@@ -315,16 +316,53 @@
                 : `Generating ${formatName}... This may take ~${estimatedTime} seconds`;
             estimateEl.textContent = estimateMsg;
 
+            // Track if modal is closed by user during download
+            let modalClosedByUser = false;
+            const onModalClose = () => {
+                modalClosedByUser = true;
+
+                // Show toast when user closes modal
+                if (window.showPDFToast) {
+                    window.showPDFToast({
+                        icon: '📥',
+                        title: isSpanish ? 'Preparando PDF...' : 'Preparing PDF...',
+                        message: isSpanish
+                            ? `Generando ${formatName}... (~${estimatedTime}s)`
+                            : `Generating ${formatName}... (~${estimatedTime}s)`,
+                        duration: estimatedTime * 1000,
+                        autoHide: false // We'll manually update it
+                    });
+                }
+            };
+
+            // Listen for modal close
+            modal.addEventListener('close', onModalClose, { once: true });
+
             console.log('Navigating to:', url);
 
             // Trigger download
             window.location.href = url;
 
-            // Keep overlay showing for estimated time, then close modal
+            // After estimated time: update toast to success or close modal
             setTimeout(() => {
                 overlay.classList.remove('active');
                 modalContent.classList.remove('loading-active');
-                document.getElementById('pdf-modal').close();
+
+                if (modalClosedByUser && window.showPDFToast) {
+                    // Update toast to success
+                    window.showPDFToast({
+                        icon: '✅',
+                        title: isSpanish ? '¡PDF Listo!' : 'PDF Ready!',
+                        message: isSpanish
+                            ? 'Revisa tu carpeta de descargas'
+                            : 'Check your downloads folder',
+                        duration: 3000,
+                        autoHide: true
+                    });
+                } else {
+                    // Close modal if still open
+                    modal.close();
+                }
             }, estimatedTime * 1000);
         }
         </script>