feat(cloudflare): add DNS pointing integration

Implement Cloudflare connection management, pointing groups and members, asynchronous A-record reconciliation, node IP triggers, admin APIs, management pages, migrations, tests, and documentation.

internal/apps/openflare/credential/sensitive.go

@@ -0,0 +1,60 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package credential seals and opens OpenFlare integration credentials.
+package credential
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"strings"
+
+	"github.com/Rain-kl/Wavelet/internal/infra/config"
+	"github.com/Rain-kl/Wavelet/pkg/util"
+)
+
+// Prefix identifies values encrypted with the current credential format.
+const Prefix = "enc:v1:"
+
+func encryptionKey() string {
+	if config.Config == nil || strings.TrimSpace(config.Config.App.SessionSecret) == "" {
+		return ""
+	}
+	sum := sha256.Sum256([]byte(config.Config.App.SessionSecret))
+	return hex.EncodeToString(sum[:])
+}
+
+// Seal trims and encrypts plaintext when a session secret is configured.
+// Plaintext storage is preserved for installations without a session secret.
+func Seal(plaintext string) (string, error) {
+	plaintext = strings.TrimSpace(plaintext)
+	if plaintext == "" {
+		return "", nil
+	}
+	key := encryptionKey()
+	if key == "" {
+		return plaintext, nil
+	}
+	encrypted, err := util.Encrypt(key, plaintext)
+	if err != nil {
+		return "", err
+	}
+	return Prefix + encrypted, nil
+}
+
+// Open decrypts a sealed value and accepts legacy plaintext values.
+func Open(stored string) (string, error) {
+	stored = strings.TrimSpace(stored)
+	if stored == "" {
+		return "", nil
+	}
+	if !strings.HasPrefix(stored, Prefix) {
+		return stored, nil
+	}
+	key := encryptionKey()
+	if key == "" {
+		return "", errors.New("cannot decrypt sensitive field without session secret")
+	}
+	return util.Decrypt(key, strings.TrimPrefix(stored, Prefix))
+}