Fix workshop matching logic to prevent false positives

- Changed from fuzzy matching (contains) to exact title matching
- Prevents "Python Fundamentals: Parts 4-6" from showing as active
  when only "Python Fundamentals: Parts 1-3" is actually scheduled
- Ensures only workshops with exact title matches in Google Sheets
  get green borders and register buttons

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

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

Author: tomvannuenen

_includes/workshop-list-sorted.html

@@ -31,7 +31,7 @@ <h3 class="text-success">
 
         {% for upcoming in site.data.upcoming_workshops.workshops %}
           {% assign upcoming_title_lower = upcoming.title | downcase %}
-          {% if upcoming_title_lower == workshop_title_lower or upcoming_title_lower contains workshop_title_lower or workshop_title_lower contains upcoming_title_lower %}
+          {% if upcoming_title_lower == workshop_title_lower %}
             {% assign is_active = true %}
             {% break %}
           {% endif %}
@@ -66,7 +66,7 @@ <h3>
 
         {% for upcoming in site.data.upcoming_workshops.workshops %}
           {% assign upcoming_title_lower = upcoming.title | downcase %}
-          {% if upcoming_title_lower == workshop_title_lower or upcoming_title_lower contains workshop_title_lower or workshop_title_lower contains upcoming_title_lower %}
+          {% if upcoming_title_lower == workshop_title_lower %}
             {% assign is_active = true %}
             {% break %}
           {% endif %}