fix(db): 修复分片查询中字段引用错误

- 将多处 metadata JSON 字段访问替换为对应的数据库列(chunk_parent_id等)
- 修正 select 语句中的排序字段，避免类型转换错误
- 优化分片计数和详情查询的条件及字段映射
- 保证查询逻辑符合当前数据库表结构，提升查询性能和准确性

src/main/resources/mapper/AiDocumentMapper.xml

@@ -20,7 +20,7 @@
         LEFT JOIN sys_user su ON vs.create_by = su.id
         WHERE vs.project_id = #{projectId}
           AND vs.deleted = 0
-          AND (vs.metadata->>'doc_id') IS NULL
+          AND vs.chunk_parent_id IS NULL
         ORDER BY vs.create_time DESC
     </select>
 
@@ -62,7 +62,7 @@
     <select id="selectChunkCount" resultType="java.lang.Integer">
         SELECT COUNT(*)
         FROM vector_store
-        WHERE metadata->>'doc_id' = #{docId}
+        WHERE chunk_parent_id = #{docId}
           AND deleted = 0
     </select>
 
@@ -102,32 +102,32 @@
     <select id="selectDocumentChunks" resultType="cn.yinlihupo.domain.vo.DocumentChunkVO">
         SELECT
             id,
-            metadata->>'doc_id' as docId,
+            chunk_parent_id as docId,
             content,
-            CAST(metadata->>'chunk_index' AS INTEGER) as chunkIndex,
-            CAST(metadata->>'chunk_total' AS INTEGER) as chunkTotal,
-            metadata->>'title' as title,
-            metadata->>'doc_type' as docType,
-            metadata->>'source_type' as sourceType,
-            metadata->>'status' as status
+            chunk_index as chunkIndex,
+            chunk_total as chunkTotal,
+            title,
+            doc_type as docType,
+            source_type as sourceType,
+            status
         FROM vector_store
-        WHERE metadata->>'doc_id' = #{docId}
+        WHERE chunk_parent_id = #{docId}
           AND deleted = 0
-        ORDER BY CAST(metadata->>'chunk_index' AS INTEGER)
+        ORDER BY chunk_index
     </select>
 
     <!-- 查询分片详情 -->
     <select id="selectChunkById" resultType="cn.yinlihupo.domain.vo.DocumentChunkVO">
         SELECT
             id,
-            metadata->>'doc_id' as docId,
+            chunk_parent_id as docId,
             content,
-            CAST(metadata->>'chunk_index' AS INTEGER) as chunkIndex,
-            CAST(metadata->>'chunk_total' AS INTEGER) as chunkTotal,
-            metadata->>'title' as title,
-            metadata->>'doc_type' as docType,
-            metadata->>'source_type' as sourceType,
-            metadata->>'status' as status
+            chunk_index as chunkIndex,
+            chunk_total as chunkTotal,
+            title,
+            doc_type as docType,
+            source_type as sourceType,
+            status
         FROM vector_store
         WHERE id = #{chunkId}
           AND deleted = 0