refactor: 修复知识库和操作指引

app/Models/Document.php

@@ -32,6 +32,7 @@ class Document extends Model
         'markdown_preview',
         'conversion_status',
         'conversion_error',
+        'knowledge_base_id',
     ];
 
     /**
@@ -42,6 +43,14 @@ class Document extends Model
         return $this->belongsTo(Group::class);
     }
 
+    /**
+     * 获取文档所属的知识库
+     */
+    public function knowledgeBase(): BelongsTo
+    {
+        return $this->belongsTo(KnowledgeBase::class);
+    }
+
     /**
      * 获取文档的上传者
      */
@@ -120,6 +129,7 @@ class Document extends Model
             'markdown_content' => $this->getMarkdownContent(),
             'type' => $this->type,
             'group_id' => $this->group_id,
+            'knowledge_base_id' => $this->knowledge_base_id,
             'uploaded_by' => $this->uploaded_by,
             'created_at' => $this->created_at?->timestamp,
         ];