feat(auth): implement user registration and login with JWT authentication

- Added `bcrypt`, `jsonwebtoken`, and `once_cell` dependencies to manage password hashing and JWT handling.
- Created `Claims` struct for JWT claims and implemented token generation in the login route.
- Implemented user registration and authentication logic in the `auth` module.
- Updated error handling to include validation errors.
- Created new routes for user registration and login, and integrated them into the main router.
- Added tests for the authentication flow, including registration and login scenarios.
- Updated user model to include a password hash field.
- Refactored user creation logic to include password validation.
- Adjusted feed and user routes to utilize JWT for authentication.

thoughts-backend/api/src/routers/feed.rs

@@ -10,7 +10,7 @@ use crate::{error::ApiError, extractor::AuthUser};
 
 #[utoipa::path(
     get,
-    path = "/",
+    path = "",
     responses(
         (status = 200, description = "Authenticated user's feed", body = ThoughtListSchema)
     ),