Refactor document handling and update Milvus collection settings

- Removed multiple failed document entries from `documents.json`.
- Added a new document entry with updated metadata and changed the index name to `regulations_dense_1024_v2`.
- Updated architecture documentation to reflect changes in the Milvus collection name.
- Adjusted requirements by removing the sqlalchemy dependency.
- Modified test cases to align with new document structure and naming conventions.
- Introduced a new test file for Milvus vector index runtime recovery and error handling.
- Updated assertions in various test files to ensure compatibility with the new schema.

tests/verify_mvp.py

@@ -65,7 +65,7 @@ def verify_migration_config() -> bool:
     try:
         assert settings.embedding_model == "text-embedding-v3"
         assert settings.embedding_dim == 1024
-        assert settings.milvus_collection == "regulations_dense_1024_v1"
+        assert settings.milvus_collection == "regulations_dense_1024_v2"
         assert settings.parser_backend == "aliyun"
         assert settings.chunk_backend == "aliyun"
         logger.info(f"embedding_model={settings.embedding_model}")