fix(server): run the remaining multi-statement service writes in one transaction

A sweep of the services for write sequences that committed step by step,
each one leaving half a change behind when the next statement failed:

- accommodations: the linked bookings' times moved after the stay's own
  transaction had committed
- airports: the boot backfill wrote a flight's two endpoints one at a
  time, and a flight left with only the first was never picked up again;
  each flight is its own transaction now
- auth: the admin settings form and a password reset (retire the old
  link, issue the new one) each land whole
- oauth: a refresh revoked the old pair before issuing the new one, so a
  failure in between logged the client out; rotating a client secret and
  revoking its tokens go together too
- oidc: the identity link, the role from the claims and the avatar of a
  returning user are one write
- addons, notification preferences: a settings save lands whole
- places: create with its tags, update, and the GPX/KML imports with
  their track colours
- trips: the trip row, the shifted leave entries and the rebuilt day grid
- vacay: a first visit provisions the plan in one transaction with a
  second look against a concurrent first visit; updatePlan fetches the
  public holidays between two transactions instead of inside its writes
- memories: a photo and its trip link, and the deletes with the orphan
  sweep behind them

AddonsService, AirportsService and OauthService take the UnitOfWork for
this. Network I/O stays outside every transaction. Comments that only
narrated the migration plan make room under the lint:size entries, which
drop with them.

server/scripts/size-baseline.json

@@ -7,17 +7,17 @@
   "src/db/repositories/Users.repository.ts": 1710,
   "src/nest/atlas/atlas-geo.ts": 1005,
   "src/nest/atlas/atlas.service.ts": 1182,
-  "src/nest/auth/auth.service.ts": 1166,
+  "src/nest/auth/auth.service.ts": 1165,
   "src/nest/budget/budget.service.ts": 1703,
   "src/nest/collections/collections.service.ts": 1488,
   "src/nest/doc-sync/doc-sync.service.ts": 1060,
   "src/nest/doc-sync/providers/synology-drive.client.ts": 1160,
   "src/nest/journey/journey-domain.service.ts": 1804,
   "src/nest/maps/maps.service.ts": 3252,
-  "src/nest/places/places.service.ts": 2022,
+  "src/nest/places/places.service.ts": 2020,
   "src/nest/plugins/plugin-runtime.service.ts": 1463,
   "src/nest/plugins/runtime/plugin-sdk.ts": 1094,
   "src/nest/reservations/reservations.service.ts": 1248,
-  "src/nest/trips/trips.service.ts": 1014,
-  "src/nest/vacay/vacay.service.ts": 1442
+  "src/nest/trips/trips.service.ts": 1013,
+  "src/nest/vacay/vacay.service.ts": 1440
 }