feat: add admin panel and update database URL

- Implemented a new admin panel that allows administrators to view
  statistics and manage weather art. The panel includes:
  - A card displaying total images and today's images
  - Buttons to generate new art and edit the city

- Added `admin?` helper method to check if the current user is an
  administrator.

- Updated database configuration to use safer credentials lookup
  method `dig` for development database URL instead of the
  previous method, improving reliability in accessing nested
  credentials.

app/helpers/application_helper.rb

@@ -21,4 +21,8 @@ module ApplicationHelper
       }
     }.to_json.html_safe if weather_art.image.attached?
   end
+
+  def admin?
+    current_user&.admin?
+  end
 end

app/views/cities/_admin_panel.html.erb

@@ -0,0 +1,45 @@
+<% if admin? %>
+  <div class="card bg-warning/10 border border-warning/20 shadow-lg p-6">
+    <div class="flex items-center gap-3 mb-4">
+      <svg xmlns="http://www.w3.org/2000/svg" class="h-6 w-6 text-warning" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 10V3L4 14h7v7l9-11h-7z" />
+      </svg>
+      <h3 class="font-display font-bold text-lg">Admin Panel</h3>
+    </div>
+
+    <div class="grid grid-cols-1 md:grid-cols-2 gap-6">
+      <!-- 统计数据 -->
+      <div class="space-y-4">
+        <h4 class="font-semibold">Statistics</h4>
+        <div class="stats stats-vertical lg:stats-horizontal shadow">
+          <div class="stat">
+            <div class="stat-title">Total Images</div>
+            <div class="stat-value"><%= @weather_art.city.weather_arts.count %></div>
+          </div>
+
+          <div class="stat">
+            <div class="stat-title">Today's Images</div>
+            <div class="stat-value"><%= @weather_art.city.weather_arts.where("created_at >= ?", Time.zone.now.beginning_of_day).count %></div>
+          </div>
+        </div>
+      </div>
+
+      <!-- 操作按钮 -->
+      <div class="space-y-4">
+        <h4 class="font-semibold">Actions</h4>
+        <div class="flex flex-wrap gap-4">
+          <%= button_to "Generate New Art", "#",
+                        method: :post,
+                        data: {
+                          controller: "generate-art",
+                          action: "generate-art#generate",
+                          city_id: @weather_art.city.id
+                        },
+                        class: "btn btn-primary" %>
+
+          <%= link_to "Edit City", edit_city_path(@weather_art.city), class: "btn btn-secondary" %>
+        </div>
+      </div>
+    </div>
+  </div>
+<% end %>

app/views/weather_arts/show.html.erb

@@ -7,7 +7,6 @@
 <div class="relative min-h-screen bg-white"> <!-- 使用更明快的背景颜色 -->
   <div class="container mx-auto px-4 pt-12 pb-16">
     <div class="max-w-6xl mx-auto space-y-6">
-
       <!-- 返回导航 -->
       <div class="flex items-center">
         <%= link_to city_path(@weather_art.city),

config/database.yml

@@ -12,7 +12,7 @@ default: &default
 development:
   <<: *default
 #  database: storage/development.sqlite3
-  url: <%= Rails.application.credentials.db_dev.url %>
+  url: <%= Rails.application.credentials.dig(:db_dev, :url) %>
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".