Promise allSettled

Requirements

• Export promiseAllSettled as the default export. Accept any iterable of values, promises, or thenables.
• Return a new promise that fulfills with an array in original iteration order. Fulfilled entries produce { status: "fulfilled", value }; rejected entries produce { status: "rejected", reason }.
• Wait until every input has settled. Input rejections are recorded as outcomes and do not reject the aggregate promise.
• Preserve original values and rejection reasons. Fulfilled outcomes have no reason property; rejected outcomes have no value property.
• Treat ordinary values as fulfilled inputs, adopt thenables, and record only their first settlement. Fulfill an empty iterable with an empty array; sparse slots become fulfilled undefined values.
• Invalid iterables or failures while reading/advancing the iterator reject the returned promise rather than throwing synchronously. This differs from an input promise rejection.
• Do not mutate the input iterable or its entries. Do not use Promise.all, Promise.allSettled, Promise.any, or Promise.race in your implementation. Promise.resolve is allowed.
• Implement ordinary Promise behavior only; subclass constructors, custom Promise constructors, cancellation, and cyclic inputs are outside the scope of this exercise.

Examples

Input: await promiseAllSettled([Promise.resolve("ready"), Promise.reject("failed")])
Output: [{ status: "fulfilled", value: "ready" }, { status: "rejected", reason: "failed" }]

Input: await promiseAllSettled([0, null])
Output: [{ status: "fulfilled", value: 0 }, { status: "fulfilled", value: null }]

Input: await promiseAllSettled([])
Output: []