admin: GET /api/integrations/admin/all 500s — populate('platformIntegration') names models that are not registered #1672

Seen live on 46e84197 (2026-09-11, UI smoke as an admin account): the admin Apps management list (frontend/src/components/AppsManagement.tsx:153 → GET /api/integrations/admin/all) answers 500 {"message":"Server error"}. Backend log, four times in the sweep:

Error fetching all integrations: MissingSchemaError: Schema hasn't been registered for model "TelegramIntegration".

Cause. backend/routes/integrations.ts:500 does Integration.find({ isActive: true }).populate('podId', …).populate('createdBy', …).populate('platformIntegration'). platformIntegration is a virtual (backend/models/Integration.ts:343) whose ref() maps telegram → 'TelegramIntegration', slack → 'SlackIntegration', discord → 'DiscordIntegration', messenger → 'MessengerIntegration'. None of those models is registered anywhere in backend/ (git grep "mongoose.model('TelegramIntegration'" → nothing), so the first Telegram row makes Mongoose throw. The mapping came in with the Slack connector (#1537 via the TS migration) and nothing registers the referenced models, so the route has been 500ing since there was a Telegram row to populate.

Not from today's deploy — #1668 touched server.ts mount order and routes/grants.ts only; the failing route and virtual are untouched since #1662.

Fix (Connectors lane's call). Either drop .populate('platformIntegration') from /admin/all (the D8 connector model keeps its platform state in config, so the virtual has nothing to join), or delete the virtual outright if no other read uses it. A route test that seeds one telegram row and expects 200 pins it.

Repro. As an admin: curl -s -o /dev/null -w '%{http_code}' https://api.commonly.me/api/integrations/admin/all -H "x-auth-token: <admin jwt>" → 500.

Other smoke tallies on the same build for context: Direction C 45/47 (+2 NA), kernel 77/80 (the 3 are the smoke account's own hosted cap), UI 25/31 — the two non-account FAILs are this 500 and a pre-#1653 placeholder description on an existing seat (decision card 67303).