feat: use xpier media library for uploads and markdown embeds

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

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

app/Models/Article.php

@@ -13,6 +13,7 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
+use Xpier\FilamentMediaLibrary\Models\MediaLibrary;
 
 class Article extends Model
 {
@@ -40,6 +41,7 @@ class Article extends Model
         'cover_path',
         'cover_source',
         'cover_status',
+        'cover_media_id',
         'cover_generated_at',
     ];
 
@@ -60,11 +62,20 @@ class Article extends Model
 
     public function hasCover(): bool
     {
+        if ($this->cover_media_id) {
+            return true;
+        }
+
         return $this->cover_status === 'ready' && filled($this->cover_path);
     }
 
     public function coverUrl(): ?string
     {
+        $libraryUrl = $this->coverMedia?->url;
+        if (filled($libraryUrl)) {
+            return (string) $libraryUrl;
+        }
+
         return app(ArticleCoverService::class)->publicUrl($this);
     }
 
@@ -123,6 +134,11 @@ class Article extends Model
         return $this->hasMany(Attachment::class);
     }
 
+    public function coverMedia(): BelongsTo
+    {
+        return $this->belongsTo(MediaLibrary::class, 'cover_media_id');
+    }
+
     public function scopeVisible(Builder $query): Builder
     {
         return $query->where('visible', true);