fix(story): remove spurious end_date from Montalcino; guard start==end range

Montalcino demo story had end_date: 2025-09-06 matching its start date,
causing a '06 – 06 Sep' range display. Removed from both the live page
and the demo source.

Template: added guard so end_date equal to the start date never renders
as a range, even if it appears in frontmatter.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vgmzx8VTTTmCskSpQtsLTr

themes/intotheeast/templates/story.html.twig

@@ -12,7 +12,7 @@
 {% endif %}
 
 {% set date_str = page.date|date('d M Y') %}
-{% if page.header.end_date %}
+{% if page.header.end_date and page.header.end_date != page.date|date('Y-m-d') %}
     {% set sd = page.date|date('d') %}
     {% set sm = page.date|date('M') %}
     {% set sy = page.date|date('Y') %}