feat: Secure OAuth callback handling

[arjankowski]

This PR improves OAuth callback handling in the login command and makes related tests more stable.

• bind callback server to loopback and keep startup error handling clear (including busy port)
• add timeout-based callback lifecycle completion to avoid hanging sessions
• keep callback handling single-use by rejecting replayed requests
• Simplify and stabilize login callback tests

[coveralls]

Pull Request Test Coverage Report for Build 23487624242

Details

• 43 of 54 (79.63%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.9%) to 84.883%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/commands/login.js	43	54	79.63%

Files with Coverage Reduction	New Missed Lines	%
src/commands/login.js	1	60.59%

Totals
Change from base Build 23444664845:	0.9%
Covered Lines:	5064
Relevant Lines:	5707

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💛 - Coveralls

[Pask423]

👍