Add tests for authentication and utilities, and update dependencies

- Created a new test package for services and added tests for AuthService.
- Implemented tests for user registration, login, and token creation.
- Added a new test package for utilities and included tests for password and JWT utilities.
- Updated `uv.lock` to include new dependencies: bcrypt, email-validator, pyjwt, and pytest-asyncio.

app/models/user.py

@@ -26,6 +26,8 @@ class User(BaseModel, table=True):
     credits: int = Field(default=0, ge=0, nullable=False)
     api_token: str | None = Field(unique=True, default=None)
     api_token_expires_at: datetime | None = Field(default=None)
+    refresh_token_hash: str | None = Field(default=None)
+    refresh_token_expires_at: datetime | None = Field(default=None)
 
     # relationships
     oauths: list["UserOauth"] = Relationship(back_populates="user")