### Description
There are several environment variables should be set:
- Frontend
- `PUBLIC_SENTRY_DSN`
- `SENTRY_AUTH_TOKEN`
- Backend
- `SENTRY_DSN`
If the dsn isn't set, errors won't be sent to Sentry.
### Package Changes
_No response_
### Screenshots
### Reference
Resolves#90
### Checklist
- [x] A milestone is set
- [x] The related issuse has been linked to this branch
Reviewed-on: #120
Co-authored-by: SquidSpirit <squid@squidspirit.com>
Co-committed-by: SquidSpirit <squid@squidspirit.com>
### Description
This PR introduces a generic authentication middleware to protect application routes. The primary goal is to prevent unauthenticated users from uploading images.
#### Changes Implemented
* **Authentication Middleware**:
* Created a new `auth_middleware` that checks the user's session for a valid `user_id`.
* If a `user_id` exists, it's added to the request extensions, making it available to downstream handlers.
* **`UserId` Extractor**:
* A `UserId` type that implements `FromRequest` has been added.
* This allows route handlers to declaratively require authentication by simply adding `user_id: UserId` as a parameter. If the user is not logged in, the extractor automatically returns an `ErrorUnauthorized` response.
* **Route Protection**:
* The `upload_image_handler` now includes the `UserId` extractor, securing the endpoint.
* A new `/auth/me` route has been added for easily verifying the logged-in user's ID during development and testing.
* **Minor Refinements**:
* The `logout_handler` now uses `session.clear()` for more robust session termination.
* Corrected the default Redis URL from `redis://127.0.1:6379` to `redis://127.0.0.1:6379`.
### Package Changes
_No response_
### Screenshots
_No response_
### Reference
Resolves#86
### Checklist
- [x] A milestone is set
- [x] The related issuse has been linked to this branch
Reviewed-on: #101
Co-authored-by: SquidSpirit <squid@squidspirit.com>
Co-committed-by: SquidSpirit <squid@squidspirit.com>
