refactor: remove frontend, move JSONs to json/ top-level

- Archive frontend to community-scripts/ProxmoxVE-Frontend-Archive
- Move frontend/public/json/ -> json/
- Update workflow paths in 5 actions:
  - update-versions-github.yml
  - update-json-date.yml
  - push-json-to-pocketbase.yml
  - delete-pocketbase-entry-on-removal.yml
  - autolabeler.yml
- Remove frontend-cicd.yml (no longer needed)
- Clean up .gitignore (remove frontend-specific entries)

json/postgresql.json

@@ -0,0 +1,55 @@
+{
+  "name": "PostgreSQL",
+  "slug": "postgresql",
+  "categories": [
+    8
+  ],
+  "date_created": "2024-05-02",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 5432,
+  "documentation": "https://www.postgresql.org/docs/",
+  "website": "https://www.postgresql.org/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/postgresql.webp",
+  "config_path": "",
+  "description": "PostgreSQL (often referred to as Postgres) is an open-source relational database management system that is known for its extensibility and strict adherence to SQL standards. It is a free and powerful database solution, suitable for a wide range of applications, from small projects to large enterprise systems. PostgreSQL is widely used for its reliability, feature-richness, and robustness.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/postgresql.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 1024,
+        "hdd": 4,
+        "os": "debian",
+        "version": "13"
+      }
+    },
+    {
+      "type": "alpine",
+      "script": "ct/alpine-postgresql.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 256,
+        "hdd": 1,
+        "os": "alpine",
+        "version": "3.23"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "Set a password after installation for postgres user by running `echo \"ALTER USER postgres with encrypted password 'your_password';\" | sudo -u postgres psql`",
+      "type": "info"
+    },
+    {
+      "text": "Debian script offers versions `15, 16, 17, 18`, while Alpine script offers versions `15, 16, 17`.",
+      "type": "info"
+    }
+  ]
+}