refactor: strategy-pattern embedder (Local/API), remove global env vars, add batch embedding

src/core/ingest.py

@@ -4,7 +4,7 @@ from dataclasses import dataclass
 from pathlib import Path
 
 from src.core.db import VectorDB
-from src.core.embedder import Embedder
+from src.core.embedder import Embedder, batch_embed
 
 
 class MarkdownSplitter:
@@ -190,9 +190,9 @@ class DocumentIngestor:
         if not chunks:
             return 0
 
-        # 嵌入
+        # 分批嵌入 (避免大文档 OOM)
         texts = [c["content"] for c in chunks]
-        embeddings = self.embedder.embed(texts)
+        embeddings = batch_embed(self.embedder, texts)
 
         # 入库
         ids = [f"{file_name}_{i}" for i in range(len(chunks))]