feat: add synchronized hover effect for PDF and print-friendly buttons

- PDF buttons (fixed, action bar, menu) now sync hover states across all instances
- Print-friendly buttons (fixed, action bar, menu) sync green hover states
- White PDF icon with red hover background (#cd6060)
- Green print button hover (#27ae60)
- Implemented using hyperscript with .pdf-hover-sync and .print-hover-sync classes
- Creates cool visual feedback showing all related buttons simultaneously

templates/partials/widgets/download-button.html

@@ -0,0 +1,17 @@
+{{define "download-button"}}
+<!-- Download PDF Button (Fixed Left) -->
+<button
+    id="download-button"
+    class="fixed-btn download-btn no-print"
+    aria-label="{{if eq .Lang "es"}}Descargar PDF{{else}}Download PDF{{end}}"
+    title="{{if eq .Lang "es"}}Descargar PDF{{else}}Download PDF{{end}}"
+    onclick="document.getElementById('pdf-modal').showModal()"
+    _="on mouseenter
+         add .pdf-hover-sync to me
+         add .pdf-hover-sync to #action-bar-pdf-btn
+       on mouseleave
+         remove .pdf-hover-sync from me
+         remove .pdf-hover-sync from #action-bar-pdf-btn">
+    <iconify-icon icon="catppuccin:pdf" width="28" height="28"></iconify-icon>
+</button>
+{{end}}