Feat v0.6.4 admin health/metrics tab + cluster merge

Admin Health tab under Monitoring with auto-refreshing runtime, DB,
cluster, and extension metrics panels. New GET /api/v1/admin/metrics
endpoint. Fattened heartbeat JSONB with stack, GC CPU%, extension
count, sandbox stats, trigger fires. Sandbox runner and trigger engine
now track cumulative execution counters. Event bus tracks publish/deliver
counts. Health endpoints consolidated via shared builder. Block renderers
(mermaid, katex, csv-table, diff-viewer) no longer require chat.
cluster-dashboard package retired — merged into admin Health tab.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/handlers/admin_metrics_test.go

@@ -0,0 +1,179 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"switchboard-core/metrics"
+	"switchboard-core/store"
+)
+
+// mockHub implements metrics.ConnCounter for tests.
+type mockHub struct{ count int }
+
+func (m *mockHub) ConnCount() int { return m.count }
+
+// mockBus implements metrics.BusCounter for tests.
+type mockBus struct{ pub, del int64 }
+
+func (m *mockBus) PublishCount() int64 { return m.pub }
+func (m *mockBus) DeliverCount() int64 { return m.del }
+
+func TestMetrics_SQLiteShape(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	collector := metrics.NewCollector(
+		nil, // no DB
+		&mockHub{count: 5},
+		&mockBus{pub: 10, del: 20},
+		store.Stores{}, // no cluster store
+		func() (uint64, uint64, float64) { return 42, 3, 12.5 },
+		func() int64 { return 7 },
+		time.Now().Add(-10*time.Minute),
+	)
+
+	h := NewMetricsHandler(collector)
+	r := gin.New()
+	r.GET("/api/v1/admin/metrics", h.GetMetrics)
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/admin/metrics", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != 200 {
+		t.Fatalf("status = %d, want 200", w.Code)
+	}
+
+	var snap metrics.Snapshot
+	if err := json.Unmarshal(w.Body.Bytes(), &snap); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	// Runtime
+	if snap.Runtime.WSClients != 5 {
+		t.Errorf("ws_clients = %d, want 5", snap.Runtime.WSClients)
+	}
+	if snap.Runtime.UptimeSec < 600 {
+		t.Errorf("uptime_sec = %f, want >= 600", snap.Runtime.UptimeSec)
+	}
+
+	// Cluster should be nil (SQLite)
+	if snap.Cluster != nil {
+		t.Errorf("cluster should be nil for SQLite, got %+v", snap.Cluster)
+	}
+
+	// Extensions
+	if snap.Extensions.StarlarkExecTotal != 42 {
+		t.Errorf("starlark_exec_total = %d, want 42", snap.Extensions.StarlarkExecTotal)
+	}
+	if snap.Extensions.StarlarkErrorsTotal != 3 {
+		t.Errorf("starlark_errors_total = %d, want 3", snap.Extensions.StarlarkErrorsTotal)
+	}
+	if snap.Extensions.StarlarkAvgDuration != 12.5 {
+		t.Errorf("starlark_avg_duration_ms = %f, want 12.5", snap.Extensions.StarlarkAvgDuration)
+	}
+	if snap.Extensions.TriggerFiresTotal != 7 {
+		t.Errorf("trigger_fires_total = %d, want 7", snap.Extensions.TriggerFiresTotal)
+	}
+	if snap.Extensions.EventBusPublished != 10 {
+		t.Errorf("event_bus_published = %d, want 10", snap.Extensions.EventBusPublished)
+	}
+	if snap.Extensions.EventBusDelivered != 20 {
+		t.Errorf("event_bus_delivered = %d, want 20", snap.Extensions.EventBusDelivered)
+	}
+}
+
+func TestMetrics_WithCluster(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	mock := &mockClusterStore{
+		nodes: []store.ClusterNode{
+			{
+				NodeID:    "node-1",
+				Endpoint:  "http://node-1:8080",
+				Heartbeat: time.Now(),
+				Stats:     json.RawMessage(`{"uptime_sec":120,"ws_clients":3}`),
+			},
+		},
+	}
+
+	collector := metrics.NewCollector(
+		nil,
+		&mockHub{count: 3},
+		&mockBus{},
+		store.Stores{Cluster: mock},
+		func() (uint64, uint64, float64) { return 0, 0, 0 },
+		func() int64 { return 0 },
+		time.Now(),
+	)
+
+	h := NewMetricsHandler(collector)
+	r := gin.New()
+	r.GET("/api/v1/admin/metrics", h.GetMetrics)
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/admin/metrics", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != 200 {
+		t.Fatalf("status = %d, want 200", w.Code)
+	}
+
+	var snap metrics.Snapshot
+	if err := json.Unmarshal(w.Body.Bytes(), &snap); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	if snap.Cluster == nil {
+		t.Fatal("cluster should not be nil with cluster store")
+	}
+	if snap.Cluster.Size != 1 {
+		t.Errorf("cluster.size = %d, want 1", snap.Cluster.Size)
+	}
+	if snap.Cluster.Nodes[0].NodeID != "node-1" {
+		t.Errorf("node_id = %q, want %q", snap.Cluster.Nodes[0].NodeID, "node-1")
+	}
+	if snap.Cluster.Nodes[0].UptimeSec != 120 {
+		t.Errorf("uptime_sec = %f, want 120", snap.Cluster.Nodes[0].UptimeSec)
+	}
+}
+
+func TestMetrics_ExtensionCounters(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	collector := metrics.NewCollector(
+		nil,
+		&mockHub{},
+		&mockBus{pub: 100, del: 500},
+		store.Stores{},
+		func() (uint64, uint64, float64) { return 1000, 50, 8.3 },
+		func() int64 { return 25 },
+		time.Now(),
+	)
+
+	h := NewMetricsHandler(collector)
+	r := gin.New()
+	r.GET("/api/v1/admin/metrics", h.GetMetrics)
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/admin/metrics", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	var snap metrics.Snapshot
+	_ = json.Unmarshal(w.Body.Bytes(), &snap)
+
+	if snap.Extensions.StarlarkExecTotal != 1000 {
+		t.Errorf("exec total = %d, want 1000", snap.Extensions.StarlarkExecTotal)
+	}
+	if snap.Extensions.EventBusPublished != 100 {
+		t.Errorf("bus published = %d, want 100", snap.Extensions.EventBusPublished)
+	}
+	if snap.Extensions.EventBusDelivered != 500 {
+		t.Errorf("bus delivered = %d, want 500", snap.Extensions.EventBusDelivered)
+	}
+}