fix(slack): Use set_user for user context in Slack event webhook

[DominikB2014]

Replace set_tag("user.email", ...) with set_user({"id", "email", "username"}) in the Slack event webhook's on_link_shared handler.

Previously, user.email was set via set_tag("user.email", ...) which stored it under the wrong attribute key, causing user.email to never appear in EAP span queries for spans with slack.event_type. Using set_user() stores the values under the correct sentry.user.* attributes that match the EAP search definitions. Also adds user.id (as string) and user.username to enrich the user context.

[linear-code]

DAIN-1475 No results for `user.email` in extensions endpoint

[cursor]

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

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit bbc6237. Configure here.}

[cursor]

User ID passed as int instead of string

Medium Severity

The id field from identity_user.id is an int, but sentry_sdk.set_user expects a string for user.id. This type mismatch can prevent the user.id attribute from being indexed or searchable correctly in EAP, as downstream storage expects a string.

 

^{Reviewed by Cursor Bugbot for commit bbc6237. Configure here.}