Tours: provenance contract, source check, one assignment path and the map overview

- P2C-02: tours record their origin (planned, GPX with file name, wanderer)
  instead of reading it off their shape; the detail answers a provenance
  contract and a trip copy keeps a tour's import record
- MF-03: a wanderer snapshot's source can be checked on purpose, read only,
  with a confirmed reimport as a new snapshot
- PR1-18: every way of putting a tour on a day shares one set of rules
- PR1-07/08: each person can hide tours from the trip map; the list shows
  each tour's line colour and the picked tour stands out on both maps

server/scripts/size-baseline.json

@@ -16,6 +16,6 @@
   "src/nest/plugins/plugin-runtime.service.ts": 1463,
   "src/nest/plugins/runtime/plugin-sdk.ts": 1093,
   "src/nest/reservations/reservations.service.ts": 1237,
-  "src/nest/trips/trips.service.ts": 1007,
+  "src/nest/trips/trips.service.ts": 1006,
   "src/nest/vacay/vacay.service.ts": 1420
 }