Add heartbeat telemetry support

src/lib/ui/components/BetaTestProgress.svelte

@@ -17,7 +17,7 @@
     const expired = $derived(test.outcome === 'inconclusive' || (!!deadline && test.outcome !== 'passed' && Date.parse(deadline) <= Date.now()));
     const ranked = $derived([...test.servers].sort((a,b) => (a.progress.some(r => r.failed) ? 0 : a.passed ? 2 : 1) - (b.progress.some(r => r.failed) ? 0 : b.passed ? 2 : 1) || a.server.localeCompare(b.server)));
     const filteredEvidence = $derived(test.evidence.filter(event => (!evidenceServer || event.server === evidenceServer)
-        && (!evidenceKind || (evidenceKind === 'gameplay' ? ['game_start','round_change','game_end'].includes(event.kind) : evidenceKind === 'health' ? ['health','status-sample'].includes(event.kind) : event.kind === evidenceKind))
+        && (!evidenceKind || (evidenceKind === 'gameplay' ? ['game_start','round_change','heartbeat','game_end'].includes(event.kind) : evidenceKind === 'health' ? ['health','status-sample'].includes(event.kind) : event.kind === evidenceKind))
         && (!evidenceQuery || `${betaEvidenceSummary(event)} ${event.payload}`.toLowerCase().includes(evidenceQuery.toLowerCase()))));
     $effect(() => { evidenceServer; evidenceKind; evidenceQuery; evidenceLimit = 25; });
     function reportAge(at:string) { const minutes=Math.max(0,Math.floor((Date.now()-Date.parse(at))/60000));return minutes<1?'less than a minute ago':minutes<60?`${minutes}m ago`:`${Math.floor(minutes/60)}h ${minutes%60}m ago`; }

src/lib/ui/components/PlayerScoreboard.svelte

@@ -94,7 +94,7 @@
         </div>
     {/if}
     <div class="scoreboard-footer">
-        <p class="note">{report.event === 'game_start' ? 'Player stats arrive with the next round report.' : report.event === 'game_end' ? 'Final stats from this game. The scoreboard resets when the next game starts.' : 'Stats update at each round change and game end.'}</p>
+        <p class="note">{report.event === 'game_start' ? 'Player stats arrive with the next round report or heartbeat.' : report.event === 'game_end' ? 'Final stats from this game. The scoreboard resets when the next game starts.' : 'Stats update at each round change, heartbeat, and game end.'}</p>
         <a href="/leaderboard">View lifetime leaderboard →</a>
     </div>
 {/if}

src/lib/ui/components/RoundTelemetry.svelte

@@ -8,7 +8,7 @@
         && (!since || Date.parse(report.receivedAt) >= Date.parse(since)));
 </script>
 
-{#if report && report.event === 'round_change' && fresh}
+{#if report && (report.event === 'round_change' || report.event === 'heartbeat') && fresh}
     <div class="round" aria-live="polite">
         <strong>Round {report.round}</strong>
         <span title={report.receivedAt}>Last reported {elapsedSince(report.receivedAt, $uiNow)} ago · {report.players.length} players</span>