fix: remove api_key from config.yaml, read from EMBED_API_KEY env var; unify config path constant

src/cli/main.py

@@ -13,7 +13,7 @@ if sys.stdout.encoding != "utf-8":
 # 确保 src 在路径中
 sys.path.insert(0, str(Path(__file__).parent.parent))
 
-from src.core.config import load_config
+from src.core.config import load_config, DEFAULT_CONFIG_PATH
 from src.core.db import VectorDB
 from src.core.embedder import create_embedder
 from src.core.ingest import DocumentIngestor
@@ -23,7 +23,7 @@ from src.core.search import Searcher
 app = typer.Typer(name="md-vector-db", help="Markdown 文档向量数据库管理工具")
 
 
-def _get_components(config_path: str = "config.yaml"):
+def _get_components(config_path: str = DEFAULT_CONFIG_PATH):
     """初始化所有组件."""
     cfg = load_config(config_path)
     db = VectorDB(persist_dir=cfg.chroma.persist_dir)