Add initial PIS route

src/lib/errors.ts

@@ -0,0 +1,17 @@
+import type { ApiEnvelope } from "@owlboard/api-schema-types";
+
+type RawErrorObject = NonNullable<ApiEnvelope.Envelope["e"]>;
+export type ApiErrorCode = NonNullable<RawErrorObject['code']>
+
+export class ApiError extends Error {
+    public readonly code: ApiErrorCode;
+    public readonly status: number;
+
+    constructor(errorObj: RawErrorObject, status: number) {
+        super(errorObj.msg || 'An unknown error occurred');
+        this.name = 'ApiError';
+        this.status = status;
+        // cast fallback to ensure it satisfies union
+        this.code = errorObj.code || ("SERVER" as ApiErrorCode);
+    }
+}