fix(demo): Update BASE_REFERENCE_DATE to November 2025

Update BASE_REFERENCE_DATE from January 15, 2025 to November 25, 2025
to ensure demo data appears recent and relevant.

This fixes the "11 meses" (11 months) display issue in GlanceableHealthHero
where lastOrchestrationRun was showing an 11-month-old timestamp.

The BASE_REFERENCE_DATE is used by all demo seeding scripts to calculate
relative dates. With the updated reference date, the most recent
orchestration runs will show as "hace 2 días" or similar instead of
"hace 11 meses".

Impact:
- All demo seed data timestamps will be relative to Nov 25, 2025
- Dashboard will show "Last run: 2 days ago" instead of "11 months ago"
- Expiration dates, delivery dates, and other temporal data remain
  properly offset from the new reference

Fixes: Issue #6 - "11 meses" data bug

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

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

shared/utils/demo_dates.py

@@ -10,7 +10,8 @@ from typing import Optional
 
 # Base reference date for all demo seed data
 # All seed scripts should use this as the "logical seed date"
-BASE_REFERENCE_DATE = datetime(2025, 1, 15, 12, 0, 0, tzinfo=timezone.utc)
+# Updated to November 2025 to show recent orchestration runs
+BASE_REFERENCE_DATE = datetime(2025, 11, 25, 12, 0, 0, tzinfo=timezone.utc)
 
 
 def adjust_date_for_demo(