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/hr.go

@@ -22,12 +22,12 @@ type Employee struct {
 	FirstName      string          `json:"first_name"`
 	LastName       string          `json:"last_name"`
 	Email          string          `json:"email"`
-	Phone          string          `json:"phone"`
+	Phone          *string         `json:"phone,omitempty"`
 	Department     string          `json:"department"`
 	Position       string          `json:"position"`
 	EmploymentType string          `json:"employment_type"`
-	Salary         float64         `json:"salary"`
-	Currency       string          `json:"currency"`
+	Salary         *float64        `json:"salary,omitempty"`
+	Currency       *string         `json:"currency,omitempty"`
 	StartDate      *time.Time      `json:"start_date"`
 	Status         string          `json:"status"`
 	CreatedAt      time.Time       `json:"created_at"`
@@ -61,7 +61,7 @@ func (h *HRHandler) ListEmployees(w http.ResponseWriter, r *http.Request) {
 		SELECT id, first_name, last_name, email, phone, department, position, 
 		       employment_type, salary, currency, start_date, status, created_at
 		FROM boc_employees
-		WHERE status = 'active'
+		WHERE status != 'deleted'
 		ORDER BY created_at DESC
 	`)
 	if err != nil {
@@ -73,11 +73,23 @@ func (h *HRHandler) ListEmployees(w http.ResponseWriter, r *http.Request) {
 	employees := []Employee{}
 	for rows.Next() {
 		var e Employee
-		if err := rows.Scan(&e.ID, &e.FirstName, &e.LastName, &e.Email, &e.Phone,
-			&e.Department, &e.Position, &e.EmploymentType, &e.Salary, &e.Currency,
+		var phone sql.NullString
+		var salary sql.NullFloat64
+		var currency sql.NullString
+		if err := rows.Scan(&e.ID, &e.FirstName, &e.LastName, &e.Email, &phone,
+			&e.Department, &e.Position, &e.EmploymentType, &salary, &currency,
 			&e.StartDate, &e.Status, &e.CreatedAt); err != nil {
 			continue
 		}
+		if phone.Valid {
+			e.Phone = &phone.String
+		}
+		if salary.Valid {
+			e.Salary = &salary.Float64
+		}
+		if currency.Valid {
+			e.Currency = &currency.String
+		}
 		employees = append(employees, e)
 	}