Improve error handling for Discord OAuth

[itsmeow]

Fixes 500 Internal Server Error from bad imports and provides much more useful and distinguished error messages, while not disclosing too much information to the user.

Also handles a missing session duration and uses the default value.

[Copilot]

Pull Request Overview

Improves Discord OAuth error handling by replacing broad exception catches with specific ones, adding distinct error messages, and introducing a default session duration when the config value is missing.

• Refactored imports to alias Client and bring in exception types
• Expanded exception handling with differentiated responses and logging
• Added fallback for missing game-session-duration and updated template rendering

Comments suppressed due to low confidence (2)

src/bapi/blueprints/discord.py:8

• [nitpick] Consider importing the exceptions module using lowercase (e.g. import discordoauth2.exceptions as exceptions) or importing specific exception classes instead of aliasing everything under Exceptions to follow PEP8 and improve clarity.

from discordoauth2.exceptions import Exceptions

src/bapi/blueprints/discord.py:84

• There are several new exception handling branches (e.g., RateLimited, Forbidden, HTTPException, KeyError) that should have corresponding unit tests to verify the correct status codes and error messages are returned.

    except Exceptions.Forbidden: