SEO-Optimierung: Meta-Tags, Open Graph, Schema.org, robots.txt, sitemap.xml, semantisches HTML und Performance-Verbesserungen (.htaccess mit GZIP & Caching)

.htaccess

@@ -1,3 +1,7 @@
+# ======================================
+# SICHERHEIT
+# ======================================
+
 # Schutz der Konfigurationsdatei
 <Files "config.php">
     Order allow,deny
@@ -10,9 +14,73 @@
     Deny from all
 </FilesMatch>
 
-# Optional: Schutz vor Directory Browsing
+# Schutz vor Directory Browsing
 Options -Indexes
 
-# Optional: PHP Fehler nicht anzeigen (für Produktivbetrieb)
+# PHP Fehler nicht anzeigen (für Produktivbetrieb)
 php_flag display_errors Off
 php_flag log_errors On
+
+# ======================================
+# SEO & PERFORMANCE
+# ======================================
+
+# HTTPS Weiterleitung (aktivieren wenn SSL verfügbar)
+# RewriteEngine On
+# RewriteCond %{HTTPS} off
+# RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
+
+# www zu non-www Weiterleitung (oder umgekehrt)
+# RewriteEngine On
+# RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
+# RewriteRule ^(.*)$ https://%1/$1 [R=301,L]
+
+# ======================================
+# GZIP KOMPRESSION
+# ======================================
+<IfModule mod_deflate.c>
+    AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css text/javascript application/javascript application/json application/xml
+</IfModule>
+
+# ======================================
+# BROWSER CACHING
+# ======================================
+<IfModule mod_expires.c>
+    ExpiresActive On
+    
+    # Bilder
+    ExpiresByType image/jpeg "access plus 1 year"
+    ExpiresByType image/png "access plus 1 year"
+    ExpiresByType image/gif "access plus 1 year"
+    ExpiresByType image/webp "access plus 1 year"
+    ExpiresByType image/svg+xml "access plus 1 year"
+    
+    # CSS und JavaScript
+    ExpiresByType text/css "access plus 1 month"
+    ExpiresByType application/javascript "access plus 1 month"
+    ExpiresByType text/javascript "access plus 1 month"
+    
+    # Fonts
+    ExpiresByType font/woff "access plus 1 year"
+    ExpiresByType font/woff2 "access plus 1 year"
+    ExpiresByType application/font-woff "access plus 1 year"
+    ExpiresByType application/font-woff2 "access plus 1 year"
+    
+    # HTML
+    ExpiresByType text/html "access plus 1 hour"
+    
+    # Favicon
+    ExpiresByType image/x-icon "access plus 1 year"
+</IfModule>
+
+# ======================================
+# MIME TYPES
+# ======================================
+<IfModule mod_mime.c>
+    AddType application/javascript js
+    AddType text/css css
+    AddType image/svg+xml svg svgz
+    AddType font/woff woff
+    AddType font/woff2 woff2
+</IfModule>
+