Start new validation system and zodified types with excc

src/util/support/types.ts

@@ -23,3 +23,10 @@ export function isKeyof<T>(key: unknown, obj: T): key is keyof T {
 export function hasOwnProperty<X extends {}, Y extends PropertyKey>(obj: X, prop: Y): obj is X & Record<Y, unknown> {  // eslint-disable-line @typescript-eslint/ban-types
     return Object.hasOwnProperty.call(obj, prop)
 }
+
+/**
+ * TypeScript helper for creating tagged-types.
+ */
+export interface TypeTag<S extends string> {
+    readonly __typeTag: S
+}