fix(teams): take query from the core facade, not a core.db that does not exist

The Team provider's db layer built its query helper as `core.db.query(...)`. The
facade has no `db` member -- every other *.db.js in this module destructures
`query` from it directly -- so every call threw `Cannot read properties of
undefined (reading 'query')`.

The failure mode is the bad part. That throw is caught by the provider's own
error handling and turned into `{ ok: false, reason: 'roster unreadable: …' }`,
which is a perfectly valid refusal -- so core would have accepted it, held the
projection it had, and reported staleness. A provider that answers correctly and
never returns data, forever, with nothing in any log louder than a warning.

Invisible to the unit tests because they stub every db function, so the helper
was never called. Found by running a real roster frame through the ingest and
then asking the provider what it saw, against the real database.

Co-Authored-By: Claude <noreply@anthropic.com>

server/model/teamProvider/teamProvider.db.js

@@ -5,9 +5,10 @@
 // core-internal (docs/website/TEAMS.md §10.3) and this module must never name
 // one, even though it is what fills them.
 
-const core = require('../../core')
-
-const query = (...args) => core.db.query(...args)
+// `query` is destructured from the core facade at require time, like every other
+// *.db.js here. The facade resolves `ctx` per call, so taking it now is safe even
+// though `ctx` does not exist yet when this file is first required.
+const { query } = require('../../core')
 
 /**
  * The guild board — one row per guild the shard has told us about.