refactor(templates): Update template definition names for admin pages

- Change template definition names from "Content" to specific page names
- Modify layout.html to conditionally render templates based on page name
- Ensure consistent template naming across admin page templates

web/templates/admin/config.html

@@ -1,4 +1,4 @@
-{{define "Content"}}
+{{define "config.html"}}
 <div class="card bg-base-100 shadow-xl">
     <div class="card-body">
         <h2 class="card-title">配置管理</h2>

web/templates/admin/layout.html

@@ -22,7 +22,13 @@
     </div>
 
     <div class="container mx-auto px-4">
-        {{template .Content .}}
+        {{if eq .Content "login.html"}}
+            {{template "login.html" .}}
+        {{else if eq .Content "metrics.html"}}
+            {{template "metrics.html" .}}
+        {{else if eq .Content "config.html"}}
+            {{template "config.html" .}}
+        {{end}}
     </div>
 
     <script src="/admin/static/js/auth.js"></script>

web/templates/admin/login.html

@@ -1,4 +1,4 @@
-{{define "Content"}}
+{{define "login.html"}}
 <div class="flex items-center justify-center min-h-[80vh]">
     <div class="card w-96 bg-base-100 shadow-xl">
         <div class="card-body">

web/templates/admin/metrics.html

@@ -1,4 +1,4 @@
-{{define "Content"}}
+{{define "metrics.html"}}
 <div class="grid grid-cols-1 md:grid-cols-2 gap-4 mb-4">
     <div class="card bg-base-100 shadow-xl">
         <div class="card-body">