🐛 Bug-fix PR

Closes #2693

📌 Summary

Updating admin privileges through the API requires mandatory fields (password, full_name), which results in unintended overwriting of existing user details.

The full_name and is_admin fields should be optional and should update the user's full_name and is_admin when they are included in the request

🔁 Reproduction Steps

1. Call the admin user update API without providing all required fields.
2. The API returns a "required field missing" error.
3. Provide all mandatory fields and update the user.

Example API Call:

curl -X 'PUT' \
  'http://localhost:4444/auth/email/admin/users/user_admin%40example.com' \
  -H "Authorization: Bearer $TOKEN" \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "email": "user_admin@example.com",
  "password": "abcd1235",
  "is_admin": true
}'

In this case, the user.full_name is going to be None and it'll be displayed as N/A in UI.

🐞 Root Cause

email, password, is_admin, and full_name are treated as mandatory fields.

If full_name is not included in the request payload, the existing full name is overwritten and becomes null / NA.

💡 Fix Description

1. Theupdate_user function in mcpgateway/routers/email_auth.py

• Replace EmailRegistrationRequest with AdminUserUpdateRequest to have fields optional.
• Handle full_name and is_admin fields from the request as optional and update them in the DB when they are available.
• Add to catch PasswordValidationError exception when the password does not meet the requirements

2. The AdminUserUpdateRequest in mcpgateway/schemas.py`

Add the optional password field to AdminUserUpdateRequest with basic min_length=8, and let the existing service validation handle the rest!

3. Add more unit tests to cover the change

🧪 Verification

📐 MCP Compliance (if relevant)

• Matches current MCP spec
• No breaking change to MCP clients

✅ Checklist

• Code formatted (make black isort pre-commit)
• No secrets/credentials committed