feat: setup Docker + MariaDB pour déploiement self-hosted

- Dockerfile (PHP 8.2 Apache + pdo_mysql)
- docker-compose.yml (househub + mariadb + Traefik househub.nas.percolouco.com)
- schema.sql (22 tables + données initiales)
- includes/db.php adapté pour variables d'environnement
- .env.example, .gitignore, README mis à jour

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,13 @@
+FROM php:8.2-apache
+
+RUN apt-get update && apt-get install -y \
+    libpng-dev libjpeg-dev libwebp-dev libzip-dev libonig-dev \
+    && docker-php-ext-install pdo pdo_mysql mysqli mbstring zip \
+    && a2enmod rewrite \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY . /var/www/html/
+
+RUN chown -R www-data:www-data /var/www/html
+
+COPY docker/apache.conf /etc/apache2/sites-available/000-default.conf