Add leaderboardId field to Achievement table (with backfill)

[tahminator]

Description of changes

Add leaderboardId field to Achievement table. This includes backfilling this data in production.

Checklist before review

• I have done a thorough self-review of the PR
• Copilot has reviewed my latest changes, and all comments have been fixed and/or closed.
• If I have made database changes, I have made sure I followed all the db repo rules listed in the wiki here. (check if no db changes)
• All tests have passed
• I have successfully deployed this PR to staging
• I have done manual QA in both dev (and staging if possible) and attached screenshots below.

Screenshots

Dev

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[github-actions]

Available PR Commands

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See: https://github.com/tahminator/codebloom/wiki/CI-Commands

[sonarqubecloud]

Quality Gate passed for 'codebloom_frontend'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed for 'codebloom_backend'

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud