Fix SSE route dependency and align architecture docs

backend/app/infrastructure/parser/vector_chunk_builder.py

@@ -0,0 +1,48 @@
+"""Implement infrastructure support for vector chunk builder."""
+
+from __future__ import annotations
+
+from app.domain.documents import Chunk, ChunkBuilder, ParsedDocument
+# Keep adapter behavior explicit so integration details remain easy to audit.
+
+
+
+class AliyunVectorChunkBuilder(ChunkBuilder):
+    """Provide the Aliyun Vector Chunk Builder builder."""
+    def build(
+        self,
+        *,
+        parsed_document: ParsedDocument,
+        regulation_type: str,
+        version: str,
+    ) -> list[Chunk]:
+        """Handle build for the Aliyun Vector Chunk Builder instance."""
+        chunks: list[Chunk] = []
+        for index, item in enumerate(parsed_document.vector_chunks):
+            content = item.get("content") or item.get("text") or ""
+            embedding_text = item.get("embedding_text") or content
+            if not embedding_text.strip():
+                continue
+            section_path = item.get("section_path") or []
+            section_title = item.get("section_title") or (section_path[-1] if section_path else "")
+            page_number = item.get("page_start") or item.get("page") or 0
+            chunk_id = item.get("chunk_id") or f"{parsed_document.doc_id}-chunk-{index}"
+            metadata = {k: v for k, v in item.items() if k not in {"content", "embedding_text"}}
+            chunks.append(
+                Chunk(
+                    chunk_id=str(chunk_id),
+                    doc_id=parsed_document.doc_id,
+                    doc_name=parsed_document.doc_name,
+                    content=content,
+                    embedding_text=embedding_text,
+                    section_title=section_title,
+                    section_path=section_path,
+                    page_number=int(page_number or 0),
+                    regulation_type=regulation_type,
+                    version=version,
+                    semantic_id=item.get("semantic_id", ""),
+                    block_type=item.get("block_type", ""),
+                    metadata=metadata,
+                )
+            )
+        return chunks