fix(oauth): send client_id on token revocation

[big-kahuna-burger]

Summary

Send client_id on OAuth token revocation by going through OAuthClient.RevokeToken instead of a raw form POST.

Depends on dash0hq/dash0-api-client-go#31, which adds ClientId to OAuthRevocationRequest. Until that ships, go.mod has a local redirect:

replace github.com/dash0hq/dash0-api-client-go => ../dash0-api-client-go

CI cannot resolve that path and will fail. Drop the replace and bump the client version once PR 31 is released on upstream.

Why

The authorization server now requires client_id on POST /oauth/revoke (RFC 7009 §2.1). Without it, logout, re-login, and config profiles update --oauth=false left the refresh token valid server-side.

Also in this PR

• oauth.RevokeRequest so API URL / client ID / refresh token cannot be swapped at call sites
• httptest handlers no longer FailNow on the server goroutine
• SamplingModeAdaptive / SamplingModeDisabled (needed to compile against the client PR, which is based on current client main)

Tests

• Revoke request body includes client_id
• --oauth=false revoke path
• Re-login revokes the old token with the old client's ID, not the new one
• Session-expired error message, interactive + agent mode

[mmanciop]

I think at least parts of this change needs to go into dash0-api-client-go so that the Terraform provider can also benefit from it

[big-kahuna-burger]

I think at least parts of this change needs to go into dash0-api-client-go so that the Terraform provider can also benefit from it

Agree, let me handle that

[big-kahuna-burger]

Thanks @mmanciop for guidance on how to land this and @nicolastakashi for detailed review. Addressed everything as far as I can see.

Both:

go test -v ./internal/oauth/
go test -v ./internal/config/ -run 'OAuthFalse|Revoke'
go test -v -tags=integration ./internal/login/ -run 'Revoke|Logout'

and

go test ./...
go test -tags=integration ./...
make lint-go
make build

Exit with 0 - logs not shown here for brevity, but you can simply checkout and run next to a local version of api client from the upstream PR: dash0hq/dash0-api-client-go#31

[mmanciop]

Converting to draft until dash0hq/dash0-api-client-go#31 ships