feat(agentctl): group remove rekey journey smoke v0.8.635

Add runGroupDmRemoveMemberRekeyJourney for E2E rekey banner validation.

Co-authored-by: Cursor <[email protected]>

headless.js

@@ -854,6 +854,25 @@ class HeadlessSession {
     return { previousChannelId: channel.id, channelId: next.id, rekey: v.dmSessionRekey }
   }
 
+  /** Phase 657: group remove member triggers encryption rekey banner. */
+  async runGroupDmRemoveMemberRekeyJourney (peerUserIds, initialName, removePeerUserId) {
+    if (!this.platform) throw new Error('headless not started')
+    const channel = await this.createGroupDm(peerUserIds, initialName)
+    if (!channel?.id) throw new Error('expected group channel')
+    const next = await this.platform.removeGroupDmMember({
+      channelId: channel.id,
+      peerUserId: removePeerUserId
+    })
+    if (!next?.id || next.id === channel.id) {
+      throw new Error('expected new channel id after remove member')
+    }
+    const v = await this.refreshView()
+    if (!v.dmSessionRekey?.channelId || v.dmSessionRekey.channelId !== next.id) {
+      throw new Error('expected dmSessionRekey after remove member')
+    }
+    return { channelId: next.id, rekey: v.dmSessionRekey }
+  }
+
   async exportGuildAuditLog (opts = {}) {
     if (!this.platform) throw new Error('headless not started')
     const out = await this.platform.exportAuditLog(opts)