Add release workflow, install.sh and update.sh for customer deployment

- release.yml: triggered by git tag v*, builds assets, creates ZIP,
  attaches to Gitea release
- install.sh: interactive first-time setup (DB config, key:generate,
  migrate, seed, cache)
- update.sh: update existing installation (clear caches, migrate, rebuild)

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

install.sh

@@ -0,0 +1,112 @@
+#!/bin/bash
+# WITshop Erstinstallation
+# Ausführen mit: bash install.sh
+
+set -e
+RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; NC='\033[0m'
+
+echo ""
+echo "=================================="
+echo "  WITshop Erstinstallation"
+echo "=================================="
+echo ""
+
+# PHP-Pfad ermitteln
+PHP=$(which php 2>/dev/null || echo "/opt/plesk/php/8.4/bin/php")
+COMPOSER=$(which composer 2>/dev/null || echo "/usr/local/psa/var/modules/composer/composer.phar")
+
+echo -e "${YELLOW}Verwendetes PHP:${NC} $PHP"
+echo -e "${YELLOW}Composer:${NC} $COMPOSER"
+echo ""
+
+# .env erstellen
+if [ -f ".env" ]; then
+  echo -e "${YELLOW}HINWEIS: .env existiert bereits. Wird nicht überschrieben.${NC}"
+else
+  echo "--- Datenbank & Shop konfigurieren ---"
+  echo ""
+
+  read -p "Shop-Name: " SHOP_NAME
+  read -p "Shop-URL (z.B. https://shop.kunde.de): " APP_URL
+  read -p "Datenbank-Host [127.0.0.1]: " DB_HOST; DB_HOST=${DB_HOST:-127.0.0.1}
+  read -p "Datenbank-Name: " DB_DATABASE
+  read -p "Datenbank-Benutzer: " DB_USERNAME
+  read -s -p "Datenbank-Passwort: " DB_PASSWORD; echo ""
+  read -p "Shop-E-Mail (Absender): " MAIL_FROM
+  read -p "SMTP-Host: " SMTP_HOST
+  read -p "SMTP-Port [587]: " SMTP_PORT; SMTP_PORT=${SMTP_PORT:-587}
+  read -p "SMTP-Benutzer: " SMTP_USER
+  read -s -p "SMTP-Passwort: " SMTP_PASS; echo ""
+
+  cat > .env << EOF
+APP_NAME="${SHOP_NAME}"
+APP_ENV=production
+APP_KEY=
+APP_DEBUG=false
+APP_URL=${APP_URL}
+
+LOG_CHANNEL=stack
+LOG_LEVEL=error
+
+DB_CONNECTION=mysql
+DB_HOST=${DB_HOST}
+DB_PORT=3306
+DB_DATABASE=${DB_DATABASE}
+DB_USERNAME=${DB_USERNAME}
+DB_PASSWORD=${DB_PASSWORD}
+
+CACHE_DRIVER=file
+SESSION_DRIVER=file
+QUEUE_CONNECTION=sync
+
+MAIL_MAILER=smtp
+MAIL_HOST=${SMTP_HOST}
+MAIL_PORT=${SMTP_PORT}
+MAIL_USERNAME=${SMTP_USER}
+MAIL_PASSWORD=${SMTP_PASS}
+MAIL_ENCRYPTION=tls
+MAIL_FROM_ADDRESS=${MAIL_FROM}
+MAIL_FROM_NAME="${SHOP_NAME}"
+EOF
+  echo -e "${GREEN}✓ .env erstellt${NC}"
+fi
+
+echo ""
+echo "--- Abhängigkeiten installieren ---"
+$PHP -d open_basedir="" $COMPOSER install --no-dev --optimize-autoloader --no-interaction
+echo -e "${GREEN}✓ Composer${NC}"
+
+echo ""
+echo "--- App-Key generieren ---"
+$PHP -d open_basedir="" artisan key:generate --force
+echo -e "${GREEN}✓ APP_KEY gesetzt${NC}"
+
+echo ""
+echo "--- Storage-Links & Berechtigungen ---"
+$PHP -d open_basedir="" artisan storage:link 2>/dev/null || true
+chmod -R 775 storage bootstrap/cache
+echo -e "${GREEN}✓ Berechtigungen gesetzt${NC}"
+
+echo ""
+echo "--- Datenbank einrichten ---"
+$PHP -d open_basedir="" artisan migrate --force
+$PHP -d open_basedir="" artisan db:seed --force
+echo -e "${GREEN}✓ Datenbank eingerichtet${NC}"
+
+echo ""
+echo "--- Cache aufbauen ---"
+$PHP -d open_basedir="" artisan config:cache
+$PHP -d open_basedir="" artisan route:cache
+$PHP -d open_basedir="" artisan view:cache
+echo -e "${GREEN}✓ Cache erstellt${NC}"
+
+echo ""
+echo "=================================="
+echo -e "${GREEN}  Installation abgeschlossen!${NC}"
+echo "=================================="
+echo ""
+echo "Nächste Schritte:"
+echo "  1. In Plesk: Dokumenten-Stammverzeichnis auf 'public' setzen"
+echo "  2. Admin-Login: ${APP_URL}/admin"
+echo "     Standard-Zugangsdaten aus dem Seeder (bitte sofort ändern!)"
+echo ""