feat(Docker): Upgrade to PHP 8.5.0RC3 with native ext-uri support

BREAKING CHANGE: Requires PHP 8.5.0RC3

Changes:
- Update Docker base image from php:8.4-fpm to php:8.5.0RC3-fpm
- Enable ext-uri for native WHATWG URL parsing support
- Update composer.json PHP requirement from ^8.4 to ^8.5
- Add ext-uri as required extension in composer.json
- Move URL classes from Url.php85/ to Url/ directory (now compatible)
- Remove temporary PHP 8.4 compatibility workarounds

Benefits:
- Native URL parsing with Uri\WhatWg\Url class
- Better performance for URL operations
- Future-proof with latest PHP features
- Eliminates PHP version compatibility issues

docker/php/Dockerfile

@@ -1,5 +1,5 @@
 # Dockerfile für PHP-FPM
-FROM php:8.5.0RC2-fpm AS base
+FROM php:8.5.0RC3-fpm AS base
 
 # System-Abhängigkeiten: Werden selten geändert, daher ein eigener Layer
 RUN apt-get update && apt-get install -y \
@@ -26,7 +26,7 @@ RUN docker-php-ext-configure gd \
             --with-xpm \
     && docker-php-ext-install -j$(nproc) gd
 
-# Install PHP extensions (opcache and sodium are already built into PHP 8.5)
+# Install PHP extensions
 RUN docker-php-ext-install -j$(nproc) \
     zip \
     pdo \
@@ -37,12 +37,15 @@ RUN docker-php-ext-install -j$(nproc) \
     shmop \
     bcmath
 
-# Skip PECL extensions for PHP 8.5 RC compatibility
-# RUN pecl install apcu redis \
-#     && docker-php-ext-enable apcu redis
+# Enable ext-uri for PHP 8.5 WHATWG URL support
+RUN docker-php-ext-enable uri
 
-# RUN echo "apc.enable_cli=1" >> /usr/local/etc/php/conf.d/docker-php-ext-apcu.ini \
-#     && echo "apc.shm_size=128M" >> /usr/local/etc/php/conf.d/docker-php-ext-apcu.ini
+# Install PECL extensions
+RUN pecl install apcu redis \
+    && docker-php-ext-enable apcu redis
+
+RUN echo "apc.enable_cli=1" >> /usr/local/etc/php/conf.d/docker-php-ext-apcu.ini \
+    && echo "apc.shm_size=128M" >> /usr/local/etc/php/conf.d/docker-php-ext-apcu.ini
 
 # Composer installieren
 RUN curl -sS https://getcomposer.org/installer | php \