Increase card height to 9.5cm, add printer margins, and fix second card placement

- Extend card bottom from y=-7.2 to y=-8.2 (8.5cm → 9.5cm per card) so the
  second card naturally lands in the lower half of the page
- Increase all margins from 0.4cm to 0.6cm for printer compatibility; scale
  front tikzpicture x-axis to 0.990cm to compensate for narrower printable width
- Increase back side row height from 2.833cm to 3.167cm (matching new card height)
  and reduce column width from 7.0cm to 6.9cm to fit within new margins
- Reduce inter-card vspace from 0.8cm to 0.6cm to prevent second card page break

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

generate_cards.py

@@ -138,7 +138,7 @@ def main():
     if args.blanko:
         blanko_output_file = Path("brevetkarte-blanko.tex")
         blanko_body = generate_blanko_card(body)
-        blanko_output = preamble + blanko_body + "\n\\vspace{0.8cm}\n\n" + blanko_body + "\n\\end{document}\n"
+        blanko_output = preamble + blanko_body + "\n\\vspace{0.6cm}\n\n" + blanko_body + "\n\\end{document}\n"
         blanko_output_file.write_text(blanko_output, encoding='utf-8')
         print(f"Generated {blanko_output_file}")
         backside_template = backside_template_file.read_text(encoding='utf-8')
@@ -171,7 +171,7 @@ def main():
     for i, card in enumerate(cards):
         document_parts.append(card)
         if i % 2 == 0 and i < len(cards) - 1:
-            document_parts.append("\n\\vspace{0.8cm}\n\n")
+            document_parts.append("\n\\vspace{0.6cm}\n\n")
         if i % 2 == 1 and i < len(cards) - 1:
             document_parts.append("\n\\newpage\n\n")