[WIP] Store Credit balance as Integer (not BigDecimal)

[MichaelBuessemeyer]

Reasoning is that big decimal is not really supported when exchanged between frontend and backend. Thus, this PR makes all credit balances now in milli credits and stores it as integers. One milli credit being the max min unit in which transactions can be done.

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• abc

TODOs:

• ...

Issues:

• fixes #8825

---

(Please delete unneeded items, merge only when none are left open)

• Added changelog entry (create a $PR_NUMBER.md file in unreleased_changes or use ./tools/create-changelog-entry.py)
• Added migration guide entry if applicable (edit the same file as for the changelog)
• Updated documentation if applicable
• Adapted wk-libs python client if relevant API parts change
• Removed dev-only changes like prints and application.conf edits
• Considered common edge cases
• Needs datastore update after deployment

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch credit-balance-integer

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}