fix: return 400 on duplicate logger name in PUT /api/logger/:id

[aabhinavvvvvvv]

Summary

Fixes #626 — renaming a logger to a duplicate name caused the server to hang with no feedback shown to the user.

Changes:

• backend/api/resources/logger.py — Duplicate name check in PUT handler, now returns 400 immediately instead of hanging.
• frontend/src/pages/profile/components/EditLoggerModal.jsx — Show error message inline when update fails.
• backend/api/schemas/cell_schema.py — Fix marshmallow 4 startup crash (missing User import).

Demo

ents_logger.mp4

[jmadden173]

/deploy

[github-actions]

PR deployed to development server

Commit: 710
SHA: 48b87df

Triggered by: @jmadden173

[jmadden173]

The implementation looks good.

TODOs:

• a unit test for the case
• adding a line in the changelog linking to the issue.
• Fix merge conflicts
• Get the linter to pass

[aabhinavvvvvvv]

@jmadden173 The workflow uses pull_request_target with a plain actions/checkout@v6 and this checks out the BASE branch (upstream/main), not our PR branch. So black is always running on upstream/main's code, and upstream/main has #from api.models.user import User (without space) in test_cell.py.

[aabhinavvvvvvv]

@jmadden173 All our tests pass (63/64). The only failure is test_get_teros_obj_fraction_scales_to_percent which is a pre-existing bug unrelated to this PR — TEROSData.get_teros_data_obj() no longer returns a vwc_unit key that the test expects. This failure exists in jlab-sensing:main independently of our changes.

[jmadden173]

Yes I see that, I did not realize how the pull request target was working when I applied that fix.