feat(auth): add admin bootstrap and username login

Initialize admin bootstrap settings during startup, persist username support in auth flows, and align frontend auth requests with local API behavior.

backend/app/config.py

@@ -3,15 +3,15 @@ from pydantic_settings import BaseSettings, SettingsConfigDict
 from typing import Literal
 
 
-BASE_DIR = Path(__file__).resolve().parent.parent
-ENV_FILE = BASE_DIR / ".env"
+REPO_ROOT = Path(__file__).resolve().parents[2]
+ENV_FILE = REPO_ROOT / ".env"
 
 
 def _resolve_path(value: str) -> str:
     path = Path(value)
     if path.is_absolute():
         return str(path)
-    return str((BASE_DIR / path).resolve())
+    return str((REPO_ROOT / path).resolve())
 
 
 class Settings(BaseSettings):
@@ -31,10 +31,10 @@ class Settings(BaseSettings):
 
     # === 数据库 ===
     DATABASE_URL: str = "sqlite+aiosqlite:///./data/jarvis.db"
-    DATA_DIR: str = "./data"
+    DATA_DIR: str = "data"
 
     # === ChromaDB ===
-    CHROMA_PERSIST_DIR: str = "./data/chroma"
+    CHROMA_PERSIST_DIR: str = "data/chroma"
 
     # === LLM 配置 ===
     # 支持: openai / claude / ollama / deepseek / custom
@@ -63,8 +63,15 @@ class Settings(BaseSettings):
     CORS_ORIGINS: list[str] = ["http://localhost:5173", "http://localhost:3000"]
 
     # === 文件上传 ===
-    UPLOAD_DIR: str = "./data/uploads"
+    UPLOAD_DIR: str = "data/uploads"
     MAX_UPLOAD_SIZE: int = 50 * 1024 * 1024
+    MINERU_LANGUAGE: Literal["ch", "en"] = "ch"
+
+    # === 管理员 bootstrap ===
+    ADMIN: str = ""
+    ADMIN_EMAIL: str = ""
+    ADMIN_PASSWORD: str = ""
+    ADMIN_FULL_NAME: str = "Administrator"
 
     # === 向量化 ===
     EMBEDDING_MODEL: str = "text-embedding-3-small"