GitLab

- Restore Gravatar functionality
- Add new button for "Use Initials"
- Set both buttons to use text-left class
- Update toast property autoClose to duration (wrong library, my bad!)
- Update toast messages to clarify that this isn't "Gravatar" but "avatar"
- Add i18n text to en-US/translation.json

Translation values for en-US are not necessary, the keys will be
used as fallback.

- `Modelfile` is a proprietary term of Ollama. `模型文件` is the Simplified Chinese translation used in their community but not common used in zh-TW community.
- `Prompt`'s better zh-TW translation is `提示詞`（refert to https://docs.aws.amazon.com/zh_tw/bedrock/latest/userguide/what-is-prompt-engineering.html ） instead of `提示`, which is easily misunderstood as a verb `建議`