feat(viewer): add severity filtering for event logs

viewer/render_test.go

@@ -270,3 +270,47 @@ func TestRenderHTMLGroupsPCIeDevicesByClass(t *testing.T) {
 		t.Fatalf("expected PCIe class groups to be sorted by device_class")
 	}
 }
+
+func TestRenderHTMLAddsSeverityFilterForEventLogs(t *testing.T) {
+	snapshot := []byte(`{
+  "target_host": "event-host",
+  "hardware": {
+    "event_logs": [
+      {
+        "component_ref": "PSU0",
+        "event_time": "2026-03-15T12:00:00Z",
+        "message": "Power restored",
+        "severity": "Info",
+        "source": "bmc"
+      },
+      {
+        "component_ref": "PSU1",
+        "event_time": "2026-03-15T12:05:00Z",
+        "message": "Power failure",
+        "severity": "Critical",
+        "source": "bmc"
+      }
+    ]
+  }
+}`)
+
+	html, err := RenderHTML(snapshot, "Reanimator Chart")
+	if err != nil {
+		t.Fatalf("RenderHTML() error = %v", err)
+	}
+
+	text := string(html)
+	for _, needle := range []string{
+		"Event Logs",
+		"All severities",
+		`<option value="critical">Critical</option>`,
+		`<option value="info">Info</option>`,
+		`data-severity="critical"`,
+		`data-severity="info"`,
+		"/static/view.js",
+	} {
+		if !strings.Contains(text, needle) {
+			t.Fatalf("expected rendered html to contain %q", needle)
+		}
+	}
+}