Add brain memory services and APIs

Introduce the backend pieces for brain memory ingestion, routing, and
system telemetry so the new knowledge workflows can project data into a
brain view. The supporting tests lock in the new behavior and keep the
expanded backend surface stable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/config.py

@@ -1,14 +1,28 @@
+from pathlib import Path
 from pydantic_settings import BaseSettings, SettingsConfigDict
 from typing import Literal
 
 
+BASE_DIR = Path(__file__).resolve().parent.parent
+ENV_FILE = BASE_DIR / ".env"
+
+
+def _resolve_path(value: str) -> str:
+    path = Path(value)
+    if path.is_absolute():
+        return str(path)
+    return str((BASE_DIR / path).resolve())
+
+
 class Settings(BaseSettings):
-    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")
+    model_config = SettingsConfigDict(env_file=str(ENV_FILE), env_file_encoding="utf-8", extra="ignore")
 
     # === 应用基础 ===
     APP_NAME: str = "Jarvis"
     APP_VERSION: str = "0.1.0"
     DEBUG: bool = False
+    HOST: str = "127.0.0.1"
+    PORT: int = 9527
 
     # === 安全 ===
     SECRET_KEY: str = "change-me-in-production"
@@ -67,3 +81,7 @@ class Settings(BaseSettings):
 
 
 settings = Settings()
+settings.DATABASE_URL = settings.DATABASE_URL.replace("./data", _resolve_path("./data"), 1)
+settings.DATA_DIR = _resolve_path(settings.DATA_DIR)
+settings.CHROMA_PERSIST_DIR = _resolve_path(settings.CHROMA_PERSIST_DIR)
+settings.UPLOAD_DIR = _resolve_path(settings.UPLOAD_DIR)