chore(slack): remove dead invite path, archive checkSlackJoins poller

Wave-based onboarding makes the auto-invite + polling path obsolete.

- Removes SlackService.inviteUserToSlack — admins now send invites
  through Slack's UI and flip the flag in our admin endpoint.
- Removes the slack_invite_failed admin alert + its detector. The
  alert no longer has a meaningful trigger (we don't attempt invites).
- Archives server/utils/checkSlackJoins.js (and its test) under
  _archive/ in case the polling pattern is needed again post-pilot.
- Deletes the Nitro plugin that scheduled checkSlackJoins on boot
  + hourly. Nothing in nitro.config / nuxt.config / package.json
  registered it elsewhere.
- Drops the slack_invite_failed branch from adminAlerts.test; the
  enum slug stays in adminAlertDismissal so historical dismissal
  rows continue to validate.

notifyNewMember (vetting-channel notification) and findUserByEmail
(used by the auto-flag helper) are retained.

tests/server/utils/adminAlerts.test.js

@@ -1,5 +1,23 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest'
 
+import {
+  ALERT_THRESHOLDS,
+  computeSignature,
+  detectNoSlackHandleAfterWeek,
+  detectStuckPendingPayment,
+  detectSuspendedMembers,
+  detectPreRegistrantSelectedNotInvited,
+  detectPreRegistrantExpired,
+  detectDraftEventsImminent,
+  detectEventsNearCapacity, detectPendingTagSuggestions , computeAllAlerts
+} from '../../../server/utils/adminAlerts.js'
+import Member from '../../../server/models/member.js'
+import PreRegistration from '../../../server/models/preRegistration.js'
+import Event from '../../../server/models/event.js'
+import TagSuggestion from '../../../server/models/tagSuggestion.js'
+
+import AdminAlertDismissal from '../../../server/models/adminAlertDismissal.js'
+
 vi.mock('../../../server/utils/mongoose.js', () => ({
   connectDB: vi.fn()
 }))
@@ -34,7 +52,6 @@ vi.mock('../../../server/models/adminAlertDismissal.js', () => ({
     find: vi.fn()
   },
   ADMIN_ALERT_TYPES: [
-    'slack_invite_failed',
     'no_slack_handle_week',
     'stuck_pending_payment',
     'member_suspended',
@@ -46,24 +63,6 @@ vi.mock('../../../server/models/adminAlertDismissal.js', () => ({
   ]
 }))
 
-import {
-  ALERT_THRESHOLDS,
-  computeSignature,
-  detectSlackInviteFailed,
-  detectNoSlackHandleAfterWeek,
-  detectStuckPendingPayment,
-  detectSuspendedMembers,
-  detectPreRegistrantSelectedNotInvited,
-  detectPreRegistrantExpired,
-  detectDraftEventsImminent,
-  detectEventsNearCapacity
-} from '../../../server/utils/adminAlerts.js'
-import Member from '../../../server/models/member.js'
-import PreRegistration from '../../../server/models/preRegistration.js'
-import Event from '../../../server/models/event.js'
-import { detectPendingTagSuggestions } from '../../../server/utils/adminAlerts.js'
-import TagSuggestion from '../../../server/models/tagSuggestion.js'
-
 describe('adminAlerts module shell', () => {
   describe('ALERT_THRESHOLDS', () => {
     it('exposes the four documented thresholds', () => {
@@ -113,36 +112,6 @@ describe('adminAlerts module shell', () => {
       })
     }
 
-    describe('detectSlackInviteFailed', () => {
-      it('returns matching members with critical severity', async () => {
-        mockMemberFind([
-          { _id: 'm1', name: 'Alex', email: 'alex@example.com' },
-          { _id: 'm2', name: 'Bea', email: 'bea@example.com' }
-        ])
-
-        const alert = await detectSlackInviteFailed()
-
-        expect(alert.type).toBe('slack_invite_failed')
-        expect(alert.severity).toBe('critical')
-        expect(alert.items).toHaveLength(2)
-        expect(alert.items[0]).toEqual({
-          id: 'm1',
-          label: 'Alex',
-          sublabel: 'alex@example.com',
-          href: '/admin/members/m1'
-        })
-        expect(Member.find).toHaveBeenCalledWith(
-          { slackInviteStatus: 'failed' }
-        )
-      })
-
-      it('returns an empty list when nothing matches', async () => {
-        mockMemberFind([])
-        const alert = await detectSlackInviteFailed()
-        expect(alert.items).toEqual([])
-      })
-    })
-
     describe('detectNoSlackHandleAfterWeek', () => {
       it('queries active members joined more than 7 days ago without a slackUserId', async () => {
         mockMemberFind([
@@ -392,9 +361,6 @@ describe('adminAlerts module shell', () => {
   })
 })
 
-import { computeAllAlerts } from '../../../server/utils/adminAlerts.js'
-import AdminAlertDismissal from '../../../server/models/adminAlertDismissal.js'
-
 describe('computeAllAlerts aggregator', () => {
   beforeEach(() => {
     vi.clearAllMocks()
@@ -423,7 +389,7 @@ describe('computeAllAlerts aggregator', () => {
 
   it('returns alerts that have items and have not been dismissed', async () => {
     Member.find.mockImplementation((query) => {
-      if (query.slackInviteStatus === 'failed') {
+      if (query.status === 'suspended') {
         return { select: vi.fn().mockReturnValue({ lean: vi.fn().mockResolvedValue([
           { _id: 'm1', name: 'Alex', email: 'alex@example.com' }
         ]) }) }
@@ -433,13 +399,13 @@ describe('computeAllAlerts aggregator', () => {
 
     const alerts = await computeAllAlerts('admin-1')
     expect(alerts).toHaveLength(1)
-    expect(alerts[0].type).toBe('slack_invite_failed')
+    expect(alerts[0].type).toBe('member_suspended')
     expect(alerts[0].signature).toMatch(/^[a-f0-9]+$/)
   })
 
   it('hides alerts whose signature matches an existing dismissal', async () => {
     Member.find.mockImplementation((query) => {
-      if (query.slackInviteStatus === 'failed') {
+      if (query.status === 'suspended') {
         return { select: vi.fn().mockReturnValue({ lean: vi.fn().mockResolvedValue([
           { _id: 'm1', name: 'Alex', email: 'alex@example.com' }
         ]) }) }
@@ -450,7 +416,7 @@ describe('computeAllAlerts aggregator', () => {
     const sig = computeSignature(['m1'])
     AdminAlertDismissal.find.mockReturnValue({
       lean: vi.fn().mockResolvedValue([
-        { adminId: 'admin-1', alertType: 'slack_invite_failed', signature: sig }
+        { adminId: 'admin-1', alertType: 'member_suspended', signature: sig }
       ])
     })
 
@@ -460,7 +426,7 @@ describe('computeAllAlerts aggregator', () => {
 
   it('shows an alert again when the underlying set changes', async () => {
     Member.find.mockImplementation((query) => {
-      if (query.slackInviteStatus === 'failed') {
+      if (query.status === 'suspended') {
         return { select: vi.fn().mockReturnValue({ lean: vi.fn().mockResolvedValue([
           { _id: 'm1', name: 'Alex', email: 'alex@example.com' },
           { _id: 'm2', name: 'Bea', email: 'bea@example.com' }
@@ -472,7 +438,7 @@ describe('computeAllAlerts aggregator', () => {
     const staleSig = computeSignature(['m1']) // dismissal was for the old single-member state
     AdminAlertDismissal.find.mockReturnValue({
       lean: vi.fn().mockResolvedValue([
-        { adminId: 'admin-1', alertType: 'slack_invite_failed', signature: staleSig }
+        { adminId: 'admin-1', alertType: 'member_suspended', signature: staleSig }
       ])
     })