Add install and setup scripts for multiple Linux distros

Introduces container setup scripts and install scripts for AlmaLinux, CentOS Stream, Devuan, Fedora, Gentoo, openEuler, openSUSE, Rocky Linux, and updates Alpine install script. Adds corresponding JSON metadata files for each distribution in the frontend. These changes enable streamlined LXC container creation and installation for a wide range of Linux distributions.

frontend/public/json/centos.json

@@ -0,0 +1,38 @@
+{
+  "name": "CentOS Stream",
+  "slug": "centos",
+  "categories": [0],
+  "date_created": "2025-12-04",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": null,
+  "documentation": "https://docs.centos.org/",
+  "website": "https://www.centos.org/centos-stream/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons/webp/centos.webp",
+  "config_path": "",
+  "description": "CentOS Stream is a continuously delivered Linux distribution that tracks just ahead of RHEL development. The upstream for the next RHEL release.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/centos.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 512,
+        "hdd": 4,
+        "os": "centos",
+        "version": "9"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": "root",
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "CentOS Stream is the upstream development platform for RHEL.",
+      "type": "info"
+    }
+  ]
+}