feat: initial project prototype (#1)

### Explanation

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### Issue

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### Attestations

- [x] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [x] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [x] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [x] I have pinned the dependencies to a specific patch version.

### Style

- [x] I have run the linter and resolved any errors.
- [x] My pull request uses an appropriate title, matching the conventional commit standards.
- [x] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

### Documentation

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### Versioning

Major - My pull request introduces a breaking change.

Reviewed-on: #1
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/modules/auth.ts

@@ -0,0 +1,24 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import type { FastifyRequest } from "fastify";
+
+/**
+ * Confirms that the auth header has been set to the correct
+ * token.
+ * @param request - The incoming Fastify request.
+ * @returns Whether the request is authenticated.
+ */
+export const auth = (request: FastifyRequest): boolean => {
+  if (request.headers.authorization === undefined) {
+    return false;
+  }
+  const token = request.headers.authorization;
+  if (token !== process.env.API_AUTH) {
+    return false;
+  }
+  return true;
+};