Fix kit login failure when trace logging is enabled

[akagami-harsh]

Description

• Modified pkg/output/client.go to use a LoggingTransport instead of wrapping the entire client struct. This ensures the client remains satisfied as an *auth.Client for the oras library while still logging requests, because The oras-go library's login function performs a strict type assertion on the registry client, requiring it to be of type *auth.Client. Previously, our trace logging mechanism wrapped this client in a custom LoggingClient struct to capture request metrics, which caused this type assertion to fail.

Linked issues

• Fixes Can't use kit login with trace debugging enabled #807 a bug where running kit login with trace logging enabled (e.g., kit login -vv) would fail with the error client type not supported

AI-Assisted Code

• This PR contains AI-generated code that I have reviewed and tested
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[akagami-harsh]

tested it on local machine

• Before

harshvir@msi:~/kitops$ go run . login -vv localhost:5000
[DEBUG] Using default config directory: /home/harshvir/.local/share/kitops
Username: test
Password: 
[ERROR] Client type not supported
exit status 1

• After

harshvir@msi:~/kitops$ git checkout fix-login-issue 
Switched to branch 'fix-login-issue'
harshvir@msi:~/kitops$ go run . login -vv localhost:5000
[DEBUG] Using default config directory: /home/harshvir/.local/share/kitops
Username: test
Password: 
[ERROR] Failed to validate the credentials for localhost:5000: Get "https://localhost:5000/v2/": dial tcp 127.0.0.1:5000: connect: connection refused
exit status 1

[Copilot]

Pull request overview

This PR fixes a bug where kit login -vv (with trace logging enabled) fails with "client type not supported" error. The issue occurs because the oras-go library's login function performs a strict type assertion requiring *auth.Client, but the previous logging implementation wrapped the client in a custom LoggingClient struct, breaking this type assertion.

Changes:

• Introduced a new LoggingTransport that wraps http.RoundTripper instead of wrapping the entire client
• Modified WrapClient() to detect *auth.Client instances and wrap their transport layer instead of wrapping the client itself
• Refactored the early return logic for improved readability

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[amisevsk]

Good idea @akagami-harsh, this is a nice solution 👍

I think we can go simpler on the implementation and drop wrapping clients entirely; whoever creates a client can just wrap their transport as necessary instead of wrapping the client. This avoids the need to do a type assertion and handle specifically authClients (since we're taking in a remote.Client interface but overriding an implementation detail within that interface).

[amisevsk]

Looks good to me! Thanks @akagami-harsh