Fix stale match liveness and stop handling (Refs #136)

tests/unit/leaderboard-ingest.test.ts

@@ -369,6 +369,39 @@ it('refreshes stats during a round without adding rounds or completing the match
     expect((await matches()).map((match) => match.status)).toEqual(['completed', 'active']);
 });
 
+it('refreshes the last report for identical heartbeats without changing participation or completed results', async () => {
+    const { serverMatchHistory } = await import('../../src/lib/server/fleet/match-history.js');
+    await report('game_start');
+    await report('heartbeat', 5, [player(undefined, { kills: 100 })]);
+    const participants = await records();
+    received += 120;
+    await report('heartbeat', 5, [player(undefined, { kills: 100 })]);
+    expect(await matches()).toHaveLength(1);
+    expect(await records()).toEqual(participants);
+    expect(serverMatchHistory(server).matches[0]).toMatchObject({
+        status: 'active',
+        lastReportedAt: '2026-09-18T20:02:02.000Z'
+    });
+    await report('game_end', 5);
+    const completed = serverMatchHistory(server).matches[0];
+    await report('game_end', 5);
+    expect(serverMatchHistory(server).matches[0]).toEqual(completed);
+});
+
+it('starts a new match when an identical heartbeat follows an interrupted match', async () => {
+    await report('heartbeat', 5);
+    const { db } = await import('../../src/lib/server/db/index.js');
+    db()
+        .prepare("UPDATE leaderboard_matches SET status='interrupted', ended_at=last_received_at")
+        .run();
+    const interrupted = (await matches())[0];
+    await report('heartbeat', 5);
+    expect(await matches()).toEqual([
+        interrupted,
+        expect.objectContaining({ status: 'active', highest_round: 5, start_observed: 0 })
+    ]);
+});
+
 it('persists independent stat high-water marks without adding cumulative snapshots or retries', async () => {
     await report('game_start');
     await report('round_change', 1);