fix(metrics): align fleet series by time bucket, harden fleet page inputs

Address review findings on the fleet metrics page.

Data correctness:
- bucket raw Sentinel samples into epoch-aligned windows (5m/30m/2h per range)
  and average them, replacing per-server LTTB. Every server now reports the
  same bucket timestamps, so the fleet sums add up point by point instead of
  zigzagging between servers (and RX+TX really combine)
- keep only the root mount in disk history, matching HasMetrics::getDiskMetrics
- leave sparkline gaps as null instead of 0, so absent samples read as gaps

Robustness:
- normalize containerMetric in mount()/updatedContainerMetric(), so
  /metrics?cmetric=foo no longer throws an undefined array key
- include the server uuid in the container row wire:key; system containers
  share one Sentinel id across servers
- round the range start to the minute so the 60s history cache can hit
- cap the Sentinel curl with --max-time 10, so one hung request cannot stall
  the serial per-server loop

UI:
- pass the spark time axis on first paint, so tooltips no longer show 1970
- show the active series name (RX/TX) in the server network chart tooltip

tests/Feature/Livewire/Fleet/MetricsChartPayloadTest.php

@@ -25,12 +25,12 @@ class ChartStubClient extends SentinelMetricsClient
         return [];
     }
 
-    public function history(string $metric, string $from): array
+    public function history(string $metric, string $range): array
     {
         return [[1000, 10.0], [2000, 20.0]];
     }
 
-    public function networkHistory(string $from): array
+    public function networkHistory(string $range): array
     {
         return ['rx' => [[1000, 5.0]], 'tx' => [[1000, 1.0]]];
     }
@@ -46,7 +46,7 @@ class ChartTestableMetrics extends Metrics
 
 class DenseChartStubClient extends ChartStubClient
 {
-    public function history(string $metric, string $from): array
+    public function history(string $metric, string $range): array
     {
         // 300 points, like a downsampled 24h host series.
         return array_map(fn ($i) => [$i * 1000, (float) $i], range(1, 300));
@@ -99,12 +99,12 @@ it('includes KPI-tile spark series aligned to one shared time axis', function ()
             $payload = $params[0];
 
             // Union of every series' buckets, sorted; each spark projects onto it,
-            // filling gaps with 0 (network only has the 1000 bucket → tail is 0).
+            // leaving gaps as null (network only has the 1000 bucket → tail is null).
             return $payload['sparkCategories'] == [1000, 2000]
                 && $payload['cpuSpark'] == [10, 20]
                 && $payload['memSpark'] == [10, 20]
                 && $payload['diskSpark'] == [10, 20]
-                && $payload['netSpark'] == [6, 0];
+                && $payload['netSpark'] === [6, null];
         });
 });
 

tests/Feature/Livewire/Fleet/MetricsDataTest.php

@@ -30,12 +30,12 @@ class StubMetricsClient extends SentinelMetricsClient
         return self::$containers[$this->server->uuid] ?? [];
     }
 
-    public function history(string $metric, string $from): array
+    public function history(string $metric, string $range): array
     {
         return [];
     }
 
-    public function networkHistory(string $from): array
+    public function networkHistory(string $range): array
     {
         return ['rx' => [], 'tx' => []];
     }
@@ -189,3 +189,41 @@ it('renders container metric values without leaking a blade directive', function
         ->assertDontSee('@break')
         ->assertSee('/s');
 });
+
+it('falls back to cpu for an unknown container metric', function () {
+    $s = metricsServer($this->team, $this->privateKey);
+    StubMetricsClient::$summaries = [$s->uuid => onlineSummary()];
+    StubMetricsClient::$containers = [$s->uuid => [
+        ['id' => 'a', 'cpu' => 5.0, 'memUsed' => 900, 'memPercent' => 9.0, 'diskBytes' => 1, 'net' => 0.0],
+    ]];
+
+    Livewire::withQueryParams(['cmetric' => 'foo'])
+        ->test(TestableMetrics::class)
+        ->assertOk()
+        ->assertSet('containerMetric', 'cpu')
+        ->set('containerMetric', 'bar')
+        ->assertSet('containerMetric', 'cpu');
+});
+
+it('keys container rows by server so shared container ids do not collide', function () {
+    $one = metricsServer($this->team, $this->privateKey);
+    $two = metricsServer($this->team, $this->privateKey);
+    $proxy = ['id' => 'coolify-proxy', 'cpu' => 1.0, 'memUsed' => 10, 'memPercent' => 1.0, 'diskBytes' => 1, 'net' => 0.0];
+
+    StubMetricsClient::$summaries = [$one->uuid => onlineSummary(), $two->uuid => onlineSummary()];
+    StubMetricsClient::$containers = [$one->uuid => [$proxy], $two->uuid => [$proxy]];
+
+    Livewire::test(TestableMetrics::class)
+        ->assertSeeHtml('wire:key="fleet-container-'.$one->uuid.'-coolify-proxy"')
+        ->assertSeeHtml('wire:key="fleet-container-'.$two->uuid.'-coolify-proxy"');
+});
+
+it('passes the spark time axis to the KPI sparklines on first paint', function () {
+    $s = metricsServer($this->team, $this->privateKey);
+    StubMetricsClient::$summaries = [$s->uuid => onlineSummary()];
+
+    $component = Livewire::test(TestableMetrics::class);
+    $component->set('chartData', ['sparkCategories' => [1700000100000], 'cpuSpark' => [12.5]]);
+
+    $component->assertSeeHtml('1700000100000');
+});