fix: login Snackbar Shows Undefined for Invalid Credentials

[DevipriyaS17]

Description
This PR fixes issue #994 where the login snackbar showed Undefined when invalid username/password was submitted.

Problem
When POST /api/v1/authorize returned 401 for bad credentials, the frontend expected a message field but did not receive a clear user-facing value, which resulted in an unclear snackbar message.

Root Cause
The invalid-credentials response did not include a user-friendly message aligned with frontend expectations.

Expected behavior
When the username or password is incorrect, the snackbar should show a clear message such as Incorrect username or password.

Screenshots

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 43.49%. Comparing base (cc77603) to head (44dd41d).

Files with missing lines	Patch %	Lines
internal/controller/openapi/devices.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1092      +/-   ##
==========================================
+ Coverage   43.44%   43.49%   +0.05%     
==========================================
  Files         143      143              
  Lines       13621    13621              
==========================================
+ Hits         5917     5924       +7     
+ Misses       7143     7135       -8     
- Partials      561      562       +1     

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[Copilot]

Pull request overview

This PR addresses issue #994 by ensuring the v1 login endpoint returns a user-friendly error message when invalid credentials are submitted, preventing the UI snackbar from displaying Undefined.

Changes:

• Update POST /api/v1/authorize invalid-credentials (401) response to include a message field with a user-friendly string.
• Add a regression test verifying the 401 response includes both error and message.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
internal/controller/httpapi/v1/login.go	Adds message to the 401 invalid-credentials JSON response.
internal/controller/httpapi/v1/login_test.go	Adds a test to assert the invalid-credentials response includes the expected message.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

[sudhir-intc]

Suggested change

	c.JSON(http.StatusUnauthorized, gin.H{errorKey: "invalid credentials", messageKey: "Incorrect username or password"})
	c.JSON(http.StatusUnauthorized, gin.H{errorKey: "invalid credentials", messageKey: "Incorrect Username and/or Password!"})

[sudhir-intc]

Have the error message consistent with MPS