Feature-flag targeting now accounts for Slack-tag-connected accounts

What

• The remote-eval (Growthbook) client context used for feature-flag experiments now includes a clientSlackTagConnected attribute, derived from slackTagConnected, and the evaluation cache key now includes slackTagConnected alongside id/organizationUUID.
• Sessions where this attribute (also called "Claude Tag") is set now skip syncRemoteEvalToDisk() entirely, so remote eval feature flags aren't written to disk for those sessions.

Why

This lets feature-flag experiments be targeted and cached separately based on whether an account has a Slack tag connected, and avoids persisting feature-flag state to disk for those sessions.