fix: use correct envVar format and enable platform services

- Fix envVar field names (key/value/description instead of name/default)
- Ghost: use MariaDB platform service instead of SQLite
- WordPress: use MariaDB platform service
- Nextcloud: use MariaDB + Redis platform services
- Gitea: use MariaDB platform service

apps/nextcloud/versions/1.0.0/config.json

@@ -1,4 +1,14 @@
 {
   "image": "nextcloud:latest",
-  "port": 80
+  "port": 80,
+  "envVars": [
+    { "key": "MYSQL_HOST", "value": "${MARIADB_HOST}", "description": "Database host (auto-injected by platform)" },
+    { "key": "MYSQL_USER", "value": "${MARIADB_USER}", "description": "Database user (auto-injected by platform)" },
+    { "key": "MYSQL_PASSWORD", "value": "${MARIADB_PASSWORD}", "description": "Database password (auto-injected by platform)" },
+    { "key": "MYSQL_DATABASE", "value": "${MARIADB_DATABASE}", "description": "Database name (auto-injected by platform)" }
+  ],
+  "platformRequirements": {
+    "mariadb": true,
+    "redis": true
+  }
 }