Integrate BACKBEAT SDK and resolve KACHING license validation

Major integrations and fixes:
- Added BACKBEAT SDK integration for P2P operation timing
- Implemented beat-aware status tracking for distributed operations
- Added Docker secrets support for secure license management
- Resolved KACHING license validation via HTTPS/TLS
- Updated docker-compose configuration for clean stack deployment
- Disabled rollback policies to prevent deployment failures
- Added license credential storage (CHORUS-DEV-MULTI-001)

Technical improvements:
- BACKBEAT P2P operation tracking with phase management
- Enhanced configuration system with file-based secrets
- Improved error handling for license validation
- Clean separation of KACHING and CHORUS deployment stacks

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/github.com/koron/go-ssdp/internal/multicast/interface.go

@@ -0,0 +1,65 @@
+package multicast
+
+import (
+	"net"
+)
+
+type InterfacesProviderFunc func() []net.Interface
+
+// InterfacesProvider specify a function to list all interfaces to multicast.
+// If no provider are given, all possible interfaces will be used.
+var InterfacesProvider InterfacesProviderFunc
+
+// interfaces gets list of net.Interface to multicast UDP packet.
+func interfaces() ([]net.Interface, error) {
+	if p := InterfacesProvider; p != nil {
+		if list := p(); len(list) > 0 {
+			return list, nil
+		}
+	}
+	return interfacesIPv4()
+}
+
+// interfacesIPv4 lists net.Interface on IPv4.
+func interfacesIPv4() ([]net.Interface, error) {
+	iflist, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+	list := make([]net.Interface, 0, len(iflist))
+	for _, ifi := range iflist {
+		if !hasLinkUp(&ifi) || !hasMulticast(&ifi) || !hasIPv4Address(&ifi) {
+			continue
+		}
+		list = append(list, ifi)
+	}
+	return list, nil
+}
+
+// hasLinkUp checks an I/F have link-up or not.
+func hasLinkUp(ifi *net.Interface) bool {
+	return ifi.Flags&net.FlagUp != 0
+}
+
+// hasMulticast checks an I/F supports multicast or not.
+func hasMulticast(ifi *net.Interface) bool {
+	return ifi.Flags&net.FlagMulticast != 0
+}
+
+// hasIPv4Address checks an I/F have IPv4 address.
+func hasIPv4Address(ifi *net.Interface) bool {
+	addrs, err := ifi.Addrs()
+	if err != nil {
+		return false
+	}
+	for _, a := range addrs {
+		ip, _, err := net.ParseCIDR(a.String())
+		if err != nil {
+			continue
+		}
+		if len(ip.To4()) == net.IPv4len && !ip.IsUnspecified() {
+			return true
+		}
+	}
+	return false
+}