test: type the follow-up steps and the Atlas visit filter as they are used

The editor follow-up always hands the planner an afterSave, and its type now
says so, so the hook test calls it under strictNullChecks. The travel stats
test reads a country without a status as visited, as the standing helper
does for the hand-marked list. The client baseline holds the one non-null
assertion the count missed.

client/scripts/eslint-baseline.json

@@ -35,7 +35,7 @@
   },
   "tests": {
     "@typescript-eslint/no-explicit-any": 490,
-    "@typescript-eslint/no-non-null-assertion": 1914,
+    "@typescript-eslint/no-non-null-assertion": 1915,
     "@typescript-eslint/no-misused-promises": 22,
     "@typescript-eslint/no-unused-vars": 51,
     "@typescript-eslint/no-floating-promises": 33,

client/src/components/Planner/useBookingFollowUp.ts

@@ -72,7 +72,7 @@ export function useBookingFollowUp({
     /** Whether a try in this session already stored the booking, so the form holds a retry. */
     holdsSaved: () => stored.current !== null,
     /** What the save hands the planner, for a booking whose files are described by `description`. */
-    steps: (description: string): BookingSaveSteps => ({
+    steps: (description: string): BookingSaveSteps & Required<Pick<BookingSaveSteps, 'afterSave'>> => ({
       saved: stored.current ?? undefined,
       afterSave: (saved) => afterSave(saved, description),
     }),

server/tests/unit/nest/travel-stats.service.test.ts

@@ -324,7 +324,7 @@ describe('place countries without a cached region (#2875)', () => {
     await cacheRegion(colosseumId, 'IT', 'IT-62');
 
     const atlasVisited = (await atlas.stats(user.id)).countries
-      .filter((c) => c.status === 'visited')
+      .filter((c) => !('status' in c) || c.status === 'visited')
       .map((c) => c.code)
       .sort();
     expect(atlasVisited).toEqual(['IT', 'VA']);