fix(login): prevent panic with --ignore-ssl-errors on subsequent runs

[conradj3]

Problem

When running octopus login --ignore-ssl-errors after an initial successful login, the CLI crashes with a panic:

panic: interface conversion: http.RoundTripper is *apiclient.SpinnerRoundTripper, not *http.Transport

This occurs because:

1. First login: HTTP client uses direct *http.Transport
2. Subsequent logins: HTTP client uses *SpinnerRoundTripper wrapping *http.Transport (for interactive spinner display)
3. The crash: Code assumed transport would always be *http.Transport and performed unsafe type assertion

Solution

Replaced the unsafe type assertion with proper type switching to handle multiple transport scenarios:

• ✅ Direct *http.Transport (first login)
• ✅ *SpinnerRoundTripper wrapping *http.Transport (subsequent logins)
• ✅ Fallback for any other transport types

Changes

• Modified SSL ignore logic in pkg/cmd/login/login.go to use type switching
• Added comprehensive test coverage in pkg/cmd/login/login_ssl_test.go
• All existing tests continue to pass

Testing

• [x] Unit tests for all transport scenarios
• [x] All existing login tests pass
• [x] CLI builds and runs successfully

Related Issues

Fixes the panic described in the original issue where users couldn't run octopus login --ignore-ssl-errors multiple times.

[CLAassistant]

All committers have signed the CLA.