fix(layout): add min-height to demo containers to prevent hidden content

SUMMARY:
Added min-h-[600px] to both demo containers to ensure content is visible.

ISSUE:
User reported 'Simulate Pressure Increase' button was hidden/not visible.
Content was rendering but container had no minimum height, causing
layout issues where buttons were hidden.

FIX:
Added min-h-[600px] to both:
- Context Pressure Monitor container
- Framework Activity Timeline container

This ensures 600px minimum height for proper content display.

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

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

public/architecture.html

@@ -372,12 +372,12 @@
 
       <div class="grid grid-cols-1 lg:grid-cols-2 gap-8">
         <!-- Context Pressure Monitor Visualization -->
-        <div class="bg-gray-50 rounded-xl shadow-lg p-6 border border-gray-200">
+        <div class="bg-gray-50 rounded-xl shadow-lg p-6 border border-gray-200 min-h-[600px]">
           <div id="pressure-chart"></div>
         </div>
 
         <!-- Framework Activity Timeline -->
-        <div class="bg-gray-50 rounded-xl shadow-lg p-6 border border-gray-200">
+        <div class="bg-gray-50 rounded-xl shadow-lg p-6 border border-gray-200 min-h-[600px]">
           <div id="activity-timeline"></div>
         </div>
       </div>