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

- Move frontend/public/json/ to json/ (top-level)
- Update all workflow path references to json/
- Delete frontend-cicd.yml workflow
- Delete frontend/ directory entirely
- Clean up .gitattributes (remove frontend entries)

json/pixelfed.json

@@ -0,0 +1,52 @@
+{
+    "name": "Pixelfed",
+    "slug": "pixelfed",
+    "categories": [
+        0
+    ],
+    "date_created": "2024-06-15",
+    "type": "ct",
+    "updateable": true,
+    "privileged": false,
+    "interface_port": 80,
+    "documentation": "https://docs.pixelfed.org/",
+    "config_path": "/opt/pixelfed/.env",
+    "website": "https://pixelfed.org/",
+    "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/pixelfed.webp",
+    "description": "Pixelfed is a free, ethical, and decentralized photo sharing platform powered by ActivityPub federation. It offers an ad-free, privacy-focused alternative to Instagram with features like Stories, Collections, and photo filters.",
+    "install_methods": [
+        {
+            "type": "default",
+            "script": "ct/pixelfed.sh",
+            "resources": {
+                "cpu": 2,
+                "ram": 2048,
+                "hdd": 10,
+                "os": "Debian",
+                "version": "12"
+            }
+        }
+    ],
+    "default_credentials": {
+        "username": null,
+        "password": null
+    },
+    "notes": [
+        {
+            "text": "Create admin account with: cd /opt/pixelfed && sudo -u pixelfed php artisan user:create",
+            "type": "warning"
+        },
+        {
+            "text": "Credentials saved in /root/pixelfed.creds",
+            "type": "info"
+        },
+        {
+            "text": "ActivityPub federation is enabled by default",
+            "type": "info"
+        },
+        {
+            "text": "Uses PostgreSQL, Redis (socket), and PHP-FPM",
+            "type": "info"
+        }
+    ]
+}