Refactor and reorganize Alembic and database configuration.

Moved Alembic files into the `app/alembic` directory and updated related paths. Consolidated database configuration in `config.py`, leveraging environment variables and ensuring centralized management. Updated Docker Compose to include `.env` files, providing a more consistent environment setup.

backend/app/core/config.py

@@ -0,0 +1,48 @@
+from pydantic_settings import BaseSettings
+from typing import Optional, List
+
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "App"
+    VERSION: str = "1.0.0"
+    API_V1_STR: str = "/api/v1"
+
+    # Database configuration
+    POSTGRES_USER: str = "postgres"
+    POSTGRES_PASSWORD: str = "postgres"
+    POSTGRES_HOST: str = "localhost"
+    POSTGRES_PORT: str = "5432"
+    POSTGRES_DB: str = "app"
+    DATABASE_URL: Optional[str] = None
+
+    @property
+    def database_url(self) -> str:
+        """
+        Get the SQLAlchemy database URL.
+        If DATABASE_URL is explicitly set, use that.
+        Otherwise, construct from components.
+        """
+        if self.DATABASE_URL:
+            return self.DATABASE_URL
+        self.DATABASE_URL = f"postgresql://{self.POSTGRES_USER}:{self.POSTGRES_PASSWORD}@{self.POSTGRES_HOST}:{self.POSTGRES_PORT}/{self.POSTGRES_DB}"
+        return self.DATABASE_URL
+
+    # JWT configuration
+    SECRET_KEY: str = "your_secret_key_here"
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+
+    # CORS configuration
+    BACKEND_CORS_ORIGINS: List[str] = ["http://localhost:3000"]
+
+    # Admin user
+    FIRST_SUPERUSER_EMAIL: Optional[str] = None
+    FIRST_SUPERUSER_PASSWORD: Optional[str] = None
+
+    class Config:
+        env_file = ".env"
+        env_file_encoding = "utf-8"
+        case_sensitive = True
+
+
+settings = Settings()

backend/app/core/database.py

@@ -1,11 +1,11 @@
 from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker
-import os
 
-SQLALCHEMY_DATABASE_URL = os.getenv("DATABASE_URL", "postgresql://postgres:postgres@db:5432/app")
+from app.core.config import settings
 
-engine = create_engine(SQLALCHEMY_DATABASE_URL)
+# Use the database URL from settings
+engine = create_engine(settings.database_url)
 SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 
 Base = declarative_base()