feat: label stale evidence data

apps/web/tests/unit/presentation.test.ts

@@ -1,7 +1,7 @@
 import assert from "node:assert/strict";
 import test from "node:test";
 
-import { activityLevel, plural } from "../../src/lib/presentation.ts";
+import { activityLevel, freshnessStatus, plural } from "../../src/lib/presentation.ts";
 import { fishVisualFamily } from "../../src/lib/fish-visuals.ts";
 import { tackleVisualKind, tackleVisualTone } from "../../src/lib/tackle-visuals.ts";
 import { waterbodyVisual } from "../../src/lib/waterbody-visuals.ts";
@@ -23,6 +23,13 @@ test("Russian plural forms cover common and exceptional endings", () => {
   );
 });
 
+test("freshness status is explicit and deterministic around the 48-hour boundary", () => {
+  const now = Date.parse("2026-09-20T12:00:00Z");
+  assert.equal(freshnessStatus("2026-09-20T11:59:00Z", now), "fresh");
+  assert.equal(freshnessStatus("2026-09-18T11:59:00Z", now), "stale");
+  assert.equal(freshnessStatus(null, now), "unknown");
+});
+
 test("fish visual families follow body type instead of a name hash", () => {
   assert.deepEqual(
     ["Щука", "Озёрная форель", "Карп", "Окунь", "Сом", "Угорь", "Палтус", "Треска", "Неизвестная рыба"].map(fishVisualFamily),