refactor(dev.py): rearrange error handling methods for better readability and maintainability
refactor(avatar.py): extract common logic into send_avatar method to reduce code duplication
refactor(remindme.py): simplify database access by directly using the reminder table
feat(case.py, note.py, reminder.py): add ensure_guild_exists method to check and create guild if not exists
refactor(case.py, note.py, reminder.py): call ensure_guild_exists before creating a new entry to ensure guild exists
feat(snippet.py): add ensure_guild_exists method to check and create guild if not exists
refactor(snippet.py): modify create_snippet method to call ensure_guild_exists before creating a snippet, ensuring guild existence