Configure browsing session pacing and size

tests/web/growth-route.test.ts

@@ -265,12 +265,13 @@ describe('growth route', () => {
         dailyTargetMin: 4,
         dailyTargetMax: 8,
         minimumGapMs: 3_600_000,
+        selectionsPerSession: 4,
       });
 
       expect(status).toBe(200);
       const parsed = GrowthAccountResponseSchema.parse(json);
       expect(parsed.account.browsing).toMatchObject({
-        settings: { enabled: true, dailyTargetMin: 4, dailyTargetMax: 8 },
+        settings: { enabled: true, dailyTargetMin: 4, dailyTargetMax: 8, selectionsPerSession: 4 },
         noVotesSubmitted: true,
       });
       expect(pushed).toContainEqual({
@@ -281,6 +282,7 @@ describe('growth route', () => {
     it.each([
       { dailyTargetMax: 13 },
       { minimumGapMs: 44 * 60_000 },
+      { selectionsPerSession: 13 },
       { postWeight: 0, commentWeight: 0 },
       { nextDueAt: 123 },
     ])('rejects unsafe or non-operator settings %o', async (body) => {