feat: #348 unify auth identifiers

[goralczyks]

📃 Ticket

#348

✍ Description

1. I've added user_identifier property for User, changed username/name to display_name for User and Whitelist User. OAS and DB have been updated accordingly
2. New user uses email for singn-up, email is stored also as user_identifier propery. lambda_auth, middlewares and routers refer to user_identifier for user auth and identification whenever applicable.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 87.65432% with 10 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
backend/oqtopus_cloud/user/middleware.py	0.00%	3 Missing ⚠️
backend/oqtopus_cloud/admin/middleware.py	33.33%	2 Missing ⚠️
backend/oqtopus_cloud/user/routers/users.py	60.00%	2 Missing ⚠️
...kend/oqtopus_cloud/common/models/whitelist_user.py	0.00%	1 Missing ⚠️
...ckend/oqtopus_cloud/lambda_auth/lambda_function.py	92.30%	1 Missing ⚠️
backend/oqtopus_cloud/user/routers/jobs.py	88.88%	1 Missing ⚠️

Files with missing lines	Coverage Δ
...end/oqtopus_cloud/admin/common/validation_utils.py	100.00% <100.00%> (ø)
backend/oqtopus_cloud/admin/routers/users.py	96.15% <100.00%> (-0.94%)	⬇️
...end/oqtopus_cloud/admin/routers/whitelist_users.py	95.31% <100.00%> (ø)
backend/oqtopus_cloud/admin/schemas/users.py	100.00% <100.00%> (ø)
...end/oqtopus_cloud/admin/schemas/whitelist_users.py	100.00% <100.00%> (ø)
backend/oqtopus_cloud/common/models/user.py	100.00% <100.00%> (ø)
backend/oqtopus_cloud/user/routers/api_token.py	100.00% <100.00%> (ø)
backend/oqtopus_cloud/user/routers/devices.py	81.42% <100.00%> (ø)
...ackend/oqtopus_cloud/user_signup/routers/signup.py	100.00% <ø> (ø)
...kend/oqtopus_cloud/common/models/whitelist_user.py	0.00% <0.00%> (ø)
... and 5 more

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[github-actions]

🚨 Potential Breaking Changes Detected: admin API 🚨

7 changes: 0 error, 7 warning, 0 info

🔍 View Detailed GitHub Action Log

Last updated: Fri, 23 Jan 2026 10:43:12 GMT

[shgokita]

Thanks, LGTM!