feat: use xpier media library for uploads and markdown embeds

Store media:ID in post bodies instead of CDN URLs, and keep sablog attach tokens as a fallback.

Co-authored-by: Cursor <cursoragent@cursor.com>

composer.json

@@ -3,7 +3,10 @@
     "name": "laravel/laravel",
     "type": "project",
     "description": "The skeleton application for the Laravel framework.",
-    "keywords": ["laravel", "framework"],
+    "keywords": [
+        "laravel",
+        "framework"
+    ],
     "license": "MIT",
     "require": {
         "php": "^8.2",
@@ -23,6 +26,7 @@
         "spatie/laravel-sitemap": "^8.0",
         "spatie/laravel-tags": "^4.0",
         "workerman/workerman": "^5.0",
+        "xpier/filament-media-library": "^1.5",
         "yansongda/pay": "^3.7"
     },
     "require-dev": {
@@ -104,5 +108,11 @@
         }
     },
     "minimum-stability": "stable",
-    "prefer-stable": true
+    "prefer-stable": true,
+    "repositories": [
+        {
+            "type": "vcs",
+            "url": "https://github.com/ffqa/xpier-filament-media-library.git"
+        }
+    ]
 }