feat: integrate Grafana dashboards into BOC DashboardPage

- Add Infrastructure Health section with CPU/Memory/Disk panels
- Add Service Status section with PM2/Docker panels
- Create GrafanaPanel component for iframe embedding
- Build passes successfully

backend/handlers/tenant.go

@@ -0,0 +1,125 @@
+package handlers
+
+import (
+	"database/sql"
+	"encoding/json"
+	"net/http"
+
+	"boc/tenant"
+)
+
+// TenantHandler hanterar multi-tenancy API
+type TenantHandler struct {
+	manager *tenant.Manager
+}
+
+func NewTenantHandler(db *sql.DB) *TenantHandler {
+	return &TenantHandler{
+		manager: tenant.NewManager(db),
+	}
+}
+
+// ListTenants returnerar alla verksamheter användaren har tillgång till
+func (h *TenantHandler) ListTenants(w http.ResponseWriter, r *http.Request) {
+	// TODO: Filtrera baserat på användarens behörigheter
+	tenants, err := h.manager.ListTenants(r.Context())
+	if err != nil {
+		http.Error(w, `{"error":"failed to list tenants"}`, http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"tenants": tenants,
+		"total":   len(tenants),
+	})
+}
+
+// GetTenant returnerar detaljer för en specifik verksamhet
+func (h *TenantHandler) GetTenant(w http.ResponseWriter, r *http.Request) {
+	tenantID := r.URL.Query().Get("id")
+	if tenantID == "" {
+		http.Error(w, `{"error":"tenant id required"}`, http.StatusBadRequest)
+		return
+	}
+
+	t, err := h.manager.GetTenant(r.Context(), tenantID)
+	if err != nil {
+		http.Error(w, `{"error":"tenant not found"}`, http.StatusNotFound)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(t)
+}
+
+// GetTenantHierarchy returnerar koncernstruktur
+func (h *TenantHandler) GetTenantHierarchy(w http.ResponseWriter, r *http.Request) {
+	// Hämta alla koncerner (root tenants)
+	rows, err := h.manager.ListTenants(r.Context())
+	if err != nil {
+		http.Error(w, `{"error":"failed to get hierarchy"}`, http.StatusInternalServerError)
+		return
+	}
+
+	// Bygg hierarki
+	type HierarchyNode struct {
+		*tenant.Tenant
+		Children []*HierarchyNode `json:"children,omitempty"`
+	}
+
+	// Simplifierad: returnera flat lista för nu
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"tenants": rows,
+	})
+}
+
+// SwitchTenant byter aktiv verksamhet för användaren
+func (h *TenantHandler) SwitchTenant(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		TenantID string `json:"tenant_id"`
+	}
+
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, `{"error":"invalid request"}`, http.StatusBadRequest)
+		return
+	}
+
+	// Verifiera att tenant finns och är aktiv
+	t, err := h.manager.GetTenant(r.Context(), req.TenantID)
+	if err != nil {
+		http.Error(w, `{"error":"tenant not found or inactive"}`, http.StatusNotFound)
+		return
+	}
+
+	// TODO: Uppdatera användarens session med ny tenant
+	// TODO: Logga tenant-byte i audit log
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"success":    true,
+		"tenant_id":  t.ID,
+		"tenant_name": t.Name,
+		"message":    "Switched to " + t.Name,
+	})
+}
+
+// GetTenantSummary returnerar sammanfattning för dashboard
+func (h *TenantHandler) GetTenantSummary(w http.ResponseWriter, r *http.Request) {
+	tenantID := r.URL.Query().Get("tenant_id")
+	if tenantID == "" {
+		tenantID = "default" // Fallback
+	}
+
+	// För nu, returnera mock-data
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"tenant_id":      tenantID,
+		"active_users":   5,
+		"customers":      3,
+		"open_deals":     3,
+		"employees":      6,
+		"pipeline_value": 5250000,
+	})
+}