feat(mig): m0007 llm_vendor存量空org_id归零为系统级0——表单启用机构过滤后存量空值不可见须归位

deploy/migrations/m0007_llm_vendor_org_backfill.json

@@ -0,0 +1,9 @@
+{
+  "id": "m0007",
+  "title": "llm_vendor 启用机构过滤：存量供应商空 org_id 归零为系统级'0'（表单改 logined_userorgid 自动注入，存量空值会被过滤不可见，须归位）",
+  "backup_tables": ["llm_vendor"],
+  "up": [
+    {"op": "sql", "sql": "UPDATE llm_vendor SET org_id='0' WHERE org_id IS NULL OR org_id=''"}
+  ],
+  "down": []
+}