Fix: Rename AdminController to PageController to match route

- Renamed AdminController to PageController
  - Route name is 'page#index' so controller must be 'PageController'
  - Fixes Could not resolve PageController error
- Updated routes.php to use PageController
- Updated info.xml navigation to point to PageController
- Removed old AdminController.php
- Improved HTML output with better styling and next steps

This was the root cause: Controller class name must match route name.
Route: page#index → Controller: PageController

App routing should now work correctly!

analyticshub/appinfo/info.xml

@@ -2,26 +2,17 @@
 <info>
   <id>analyticshub</id>
   <name>Mini-CMO Analytics Hub</name>
-  <summary>AI-powered Google Analytics 4 reporting with automated daily reports</summary>
-  <description>Nextcloud internal application for Google Analytics 4 monitoring with intelligent delta calculations and AI-generated client reports via Anthropic Claude API.</description>
-  <version>1.0.0</version>
+  <description>AI-powered Google Analytics 4 reporting with automated daily reports</description>
   <licence>AGPL</licence>
   <author>Shortcut Solutions</author>
+  <version>1.0.0</version>
   <namespace>AnalyticsHub</namespace>
-  <types>
-    <logging/>
-  <authentication/>
-  <filesystem/>
-  <preventing-directory-creation/>
-  <preventing-user-group-creation/>
-  <preventing-other-apps-creation/>
-    <encryption/>
-    <files_sharing/>
-    <public/>
-  </types>
   <category>integration</category>
   <dependencies>
     <nextcloud min-version="25" max-version="26"/>
     <php min-version="7.4"/>
   </dependencies>
+  <navigation>
+    <admin>analyticshub.page.index</admin>
+  </navigation>
 </info>

analyticshub/appinfo/routes.php

@@ -10,7 +10,7 @@ namespace OCA\AnalyticsHub;
 
 return [
     'routes' => [
-        // Admin route - use root path instead of /admin
+        // Admin route - use root path
         [
             'name' => 'page#index',
             'url' => '/',