Add ChilliCream UnsignedInt scalar (#59)

Author: glen-84

scalars/contributed/chillicream/unsigned-int.md

@@ -0,0 +1,104 @@
+# UnsignedInt — GraphQL Custom Scalar
+
+Author – ChilliCream
+
+Date – 2026-01-09
+
+**License and Copyright**
+
+Copyright © GraphQL contributors. This specification is licensed under
+[OWFa 1.0](https://www.openwebfoundation.org/the-agreements/the-owf-1-0-agreements-granted-claims/owfa-1-0).
+
+# Overview
+
+The `UnsignedInt` scalar type represents an unsigned 32-bit integer. It is
+intended for scenarios where values are constrained to the range 0 to
+4,294,967,295, such as representing counts, sizes, indices, or other
+non-negative integer values.
+
+Unlike the built-in `Int` scalar which represents signed 32-bit integers with a
+range of -2,147,483,648 to 2,147,483,647, `UnsignedInt` provides stronger type
+safety for values that must be non-negative and can represent larger positive
+values.
+
+# Recommended name
+
+The recommended name for this scalar is `UnsignedInt`.
+
+# Result spec
+
+An `UnsignedInt` scalar must serialize to an integer value in the range 0 to
+4,294,967,295 (inclusive).
+
+## Examples
+
+These are valid result values:
+
+| Value        | Explanation                           |
+| ------------ | ------------------------------------- |
+| `0`          | Minimum unsigned int value.           |
+| `4294967295` | Maximum unsigned int value.           |
+| `2147483648` | A value exceeding signed int maximum. |
+
+These are invalid result values:
+
+| Value        | Why is it invalid                   |
+| ------------ | ----------------------------------- |
+| `-1`         | Negative values are not allowed.    |
+| `4294967296` | Exceeds maximum unsigned int value. |
+| `3.14`       | Fractional values are not allowed.  |
+| `"1000"`     | Must be a number, not a string.     |
+
+# Input spec
+
+An `UnsignedInt` scalar accepts integer values in the range 0 to 4,294,967,295
+(inclusive), both as GraphQL literals and as JSON input values.
+
+Implementations should validate:
+
+- Value is an integer (no fractional component)
+- Value is between 0 and 4,294,967,295 (inclusive)
+- Value is not negative
+
+## Examples
+
+Valid input values:
+
+GraphQL Literal:
+
+```graphql
+query {
+  items(limit: 100, offset: 50) {
+    id
+  }
+}
+```
+
+JSON input:
+
+```json
+{
+  "limit": 100,
+  "offset": 50
+}
+```
+
+```json
+{
+  "count": 4294967295
+}
+```
+
+Invalid input values:
+
+| Value        | Why is it invalid                   |
+| ------------ | ----------------------------------- |
+| `-1`         | Negative values are not allowed.    |
+| `4294967296` | Exceeds maximum unsigned int value. |
+| `3.14`       | Fractional values are not allowed.  |
+| `"1000"`     | Must be a number, not a string.     |
+
+# References
+
+- [GraphQL Specification - Int](https://spec.graphql.org/September2025/#sec-Int)
+  — Built-in integer scalar type