feat: add nftables forwarding mode

go-backend/internal/runtime/nftables/manager.go

@@ -0,0 +1,54 @@
+package nftables
+
+import (
+	"context"
+	"errors"
+)
+
+type Manager struct {
+	runner Runner
+}
+
+func NewManager(runner Runner) *Manager {
+	if runner == nil {
+		runner = NewSSHRunner()
+	}
+	return &Manager{runner: runner}
+}
+
+func (m *Manager) Test(ctx context.Context, cfg SSHConfig) error {
+	if err := m.ensureInitialized(); err != nil {
+		return err
+	}
+	return m.runner.Test(ctx, cfg)
+}
+
+func (m *Manager) Reconcile(ctx context.Context, cfg SSHConfig, plan NodePlan) (ApplyResult, error) {
+	if err := m.ensureInitialized(); err != nil {
+		return ApplyResult{}, err
+	}
+	result := ApplyResult{
+		NodeID: plan.NodeID,
+		Script: RenderTable(plan),
+		Hashes: PlanHashes(plan),
+	}
+	if err := m.runner.ApplyScript(ctx, cfg, result.Script); err != nil {
+		return ApplyResult{}, err
+	}
+	return result, nil
+}
+
+func (m *Manager) Clear(ctx context.Context, cfg SSHConfig) error {
+	if err := m.ensureInitialized(); err != nil {
+		return err
+	}
+	script := RenderTable(NodePlan{})
+	return m.runner.ApplyScript(ctx, cfg, script)
+}
+
+func (m *Manager) ensureInitialized() error {
+	if m == nil || m.runner == nil {
+		return errors.New("nftables manager not initialized")
+	}
+	return nil
+}