Fixes + stable gateway ids

api/proto/common/money/v1/money.proto

@@ -2,22 +2,39 @@ syntax = "proto3";
 package common.money.v1;
 option go_package = "github.com/tech/sendico/pkg/proto/common/money/v1;moneyv1";
 
-message Decimal { string value = 1; } // exact decimal as string
-
-message Money {
-  string amount   = 1; // decimal string
-  string currency = 2; // ISO 4217 or your code set
+// Decimal represents an exact decimal value encoded as a string to avoid
+// floating-point precision loss.
+message Decimal {
+  // value is the decimal string representation (e.g. "123.45").
+  string value = 1;
 }
 
+// Money pairs a decimal amount with a currency code.
+message Money {
+  // amount is the decimal string representation.
+  string amount   = 1;
+  // currency is the ISO 4217 currency code (e.g. "USD", "EUR").
+  string currency = 2;
+}
+
+// RoundingMode specifies how to round monetary calculations.
 enum RoundingMode {
+  // ROUNDING_MODE_UNSPECIFIED is the default zero value.
   ROUNDING_MODE_UNSPECIFIED = 0;
+  // ROUND_HALF_EVEN rounds to the nearest even digit (banker's rounding).
   ROUND_HALF_EVEN = 1;
+  // ROUND_HALF_UP rounds halves away from zero.
   ROUND_HALF_UP   = 2;
+  // ROUND_DOWN truncates towards zero.
   ROUND_DOWN      = 3;
 }
 
+// CurrencyMeta describes the precision and rounding rules for a currency.
 message CurrencyMeta {
+  // code is the ISO 4217 currency code.
   string code = 1;
+  // decimals is the number of minor-unit digits (e.g. 2 for USD, 0 for JPY).
   uint32 decimals = 2;
+  // rounding is the preferred rounding mode for this currency.
   RoundingMode rounding = 3;
 }