Add PVE script-creator agent; remove legacy scripts

Add a new .github agent (pve-script-creator.agent.md) with workflow and strict rules for generating CT/install/json files. Remove legacy CT/install/json artifacts for alpine-ironclaw and openthread-br (ct/, install/, json/ entries deleted). Also adjust mqttx update logic: set CLEAN_INSTALL=1 and move the update msg_info after fetch_and_deploy_gh_release to ensure a clean deployment before reporting/updating and then run yarn build in the app web dir.

json/openthread-br.json

@@ -1,48 +0,0 @@
-{
-    "name": "OpenThread Border Router",
-    "slug": "openthread-br",
-    "categories": [
-        17
-    ],
-    "date_created": "2026-03-30",
-    "type": "ct",
-    "updateable": true,
-    "privileged": true,
-    "interface_port": 80,
-    "documentation": "https://openthread.io/guides/border-router",
-    "website": "https://openthread.io/",
-    "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/openthread.webp",
-    "config_path": "/etc/default/otbr-agent",
-    "description": "OpenThread Border Router (OTBR) connects a Thread network to other IP-based networks such as Wi-Fi or Ethernet, providing bidirectional connectivity, mDNS/SRP service discovery, NAT64, and external Thread commissioning.",
-    "install_methods": [
-        {
-            "type": "default",
-            "script": "ct/openthread-br.sh",
-            "resources": {
-                "cpu": 2,
-                "ram": 2048,
-                "hdd": 4,
-                "os": "Debian",
-                "version": "13"
-            }
-        }
-    ],
-    "default_credentials": {
-        "username": null,
-        "password": null
-    },
-    "notes": [
-        {
-            "text": "Requires a Thread Radio Co-Processor (RCP) device. USB: pass through to LXC (e.g. /dev/ttyACM0). TCP: use socat forkpty pattern (see `/etc/default/otbr-agent` for examples).",
-            "type": "warning"
-        },
-        {
-            "text": "Services are enabled but not started at install. Configure `/etc/default/otbr-agent` with your RCP device, then run: `systemctl restart otbr-agent otbr-web`",
-            "type": "info"
-        },
-        {
-            "text": "Home Assistant: Add 'OpenThread Border Router' integration with URL `http://<IP>:8081`. Web UI is on port 80.",
-            "type": "info"
-        }
-    ]
-}