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/multiformats/go-multihash/set.go

@@ -0,0 +1,66 @@
+package multihash
+
+// Set is a set of Multihashes, holding one copy per Multihash.
+type Set struct {
+	set map[string]struct{}
+}
+
+// NewSet creates a new set correctly initialized.
+func NewSet() *Set {
+	return &Set{
+		set: make(map[string]struct{}),
+	}
+}
+
+// Add adds a new multihash to the set.
+func (s *Set) Add(m Multihash) {
+	s.set[string(m)] = struct{}{}
+}
+
+// Len returns the number of elements in the set.
+func (s *Set) Len() int {
+	return len(s.set)
+}
+
+// Has returns true if the element is in the set.
+func (s *Set) Has(m Multihash) bool {
+	_, ok := s.set[string(m)]
+	return ok
+}
+
+// Visit adds a multihash only if it is not in the set already.  Returns true
+// if the multihash was added (was not in the set before).
+func (s *Set) Visit(m Multihash) bool {
+	_, ok := s.set[string(m)]
+	if !ok {
+		s.set[string(m)] = struct{}{}
+		return true
+	}
+	return false
+}
+
+// ForEach runs f(m) with each multihash in the set. If returns immediately if
+// f(m) returns an error.
+func (s *Set) ForEach(f func(m Multihash) error) error {
+	for elem := range s.set {
+		mh := Multihash(elem)
+		if err := f(mh); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Remove removes an element from the set.
+func (s *Set) Remove(m Multihash) {
+	delete(s.set, string(m))
+}
+
+// All returns a slice with all the elements in the set.
+func (s *Set) All() []Multihash {
+	out := make([]Multihash, 0, len(s.set))
+	for m := range s.set {
+		out = append(out, Multihash(m))
+	}
+	return out
+}