Add journal entry metadata/NLP analysis and UI

[alexpunct]

As a user I would like to be able to track my mood across time so I can see if my happiness is improving.

Proposed implementation:

Use ChatGPT to generate the metadata for each post and return it as JSON. The metadata could contain the sentiment (negative, neutral, positive), the topics extracted from the entry.
Show a graph of the mood across time and a list of topics (like a tag cloud) than when clicked displays all entries with that topic.