Add mineral search and permalink pages

- Search bar toggle in header (magnifying glass icon)
- /daily-stone/search/?q= endpoint with results list
- /daily-stone/mineral/<id>/ permalink for each mineral
- Mineral count shown in footer

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

dailystone/urls.py

@@ -7,4 +7,6 @@ app_name = 'dailystone'
 urlpatterns = [
     path('', views.daily_stone, name='daily_stone'),
     path('random/', views.random_stone, name='random_stone'),
+    path('search/', views.search_minerals, name='search'),
+    path('mineral/<int:pk>/', views.mineral_detail, name='mineral_detail'),
 ]