feat(slack): Add frontend pipeline step for Slack integration setup

[evanpurkhiser]

Register the Slack integration in the pipeline registry with a single
OAuthLoginStep component. This is the simplest integration frontend since
Slack only requires an OAuth authorization flow with no additional
configuration steps.

Ref VDY-42

[linear-code]

VDY-42 Slack: API-driven integration setup

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

New OAuth step duplicates existing GitLab implementation

Low Severity

SlackOAuthLoginStep is nearly identical to GitLabOAuthLoginStep in pipelineIntegrationGitLab.tsx — same type signature, same handleOAuthCallback body, same OAuthLoginStep rendering — differing only in serviceName and the popup option. As more OAuth-only integrations are added, this boilerplate will keep getting copied. A small shared factory (parameterized by serviceName and optional PopupOptions) would eliminate the duplication.

 

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