Organize backend into product executable and shared Go modules

backend/shared/database/repository/index/index.go

@@ -0,0 +1,25 @@
+package repository
+
+import "git.sendico.io/tech/sxchnge/shared/database/repository/builder"
+
+type Sort int8
+
+const (
+	Asc  Sort = 1
+	Desc Sort = -1
+)
+
+type Key struct {
+	Field string
+	Sort  Sort      // 1 or -1. 0 means “use Type”.
+	Type  IndexType // optional: "text", "2dsphere", ...
+}
+
+type Definition struct {
+	Keys          []Key         // mandatory, at least one element
+	Unique        bool          // unique constraint?
+	Sparse        bool          // sparse?
+	TTL           *int32        // seconds; nil means “no TTL”
+	Name          string        // optional explicit name
+	PartialFilter builder.Query // optional: partialFilterExpression for conditional indexes
+}