Fix day number styling for today in print preview

The day number text for today's date was still showing the special
blue color styling in print preview. This adds a specific rule to
reset the .day-number color and font-weight for today's date.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/print-preview.css

@@ -239,6 +239,11 @@
     box-shadow: none !important;
 }
 
+.print-preview-paper .calendar-day.today .day-number {
+    color: var(--text-color, #333) !important;
+    font-weight: normal !important;
+}
+
 /* Remove selected day highlighting in preview */
 .print-preview-paper .calendar-day.selected {
     background-color: transparent !important;