feat: edge gateway service

gateway/internal/clock/clock.go

@@ -0,0 +1,20 @@
+// Package clock provides the gateway time source abstraction used by
+// authenticated transport checks.
+package clock
+
+import "time"
+
+// Clock returns current server time for freshness checks and time-dependent
+// transport behavior.
+type Clock interface {
+	// Now returns the current server time.
+	Now() time.Time
+}
+
+// System returns the current process time using the local system clock.
+type System struct{}
+
+// Now returns the current UTC time from the system clock.
+func (System) Now() time.Time {
+	return time.Now().UTC()
+}