refactor: enforce mandatory brackets for composite values

Implements Phase 1 and 2 of the syntax rework plan:
- Brackets `[]` are now mandatory for all tuple and array values.
- Removed the `[Type][]` array syntax; arrays now only use `Type[]`.
- `[single]` is now strictly a 1-tuple rather than an array.
- Updated documentation and test fixtures to reflect these breaking
  changes.

src/type-utils.ts

@@ -39,13 +39,6 @@ export function schemaToTypeString(
       return schema.isOptional ? `${baseType} | null` : baseType;
     }
     case "array":
-      if (schema.element.type === "tuple") {
-        const tupleElements = schema.element.elements.map((el) => {
-          const typeStr = schemaToTypeString(el.schema, resourceNames);
-          return el.name ? `${el.name}: ${typeStr}` : typeStr;
-        });
-        return `[${tupleElements.join(", ")}][]`;
-      }
       const elementType = schemaToTypeString(schema.element, resourceNames);
       if (schema.element.type === "union") {
         return `(${elementType})[]`;