LnurlResponse.from_dict raises on valid LUD-06 pay callback when `routes` is omitted

[dsbaars]

LnurlResponse.from_dict incorrectly rejects a valid LUD-06 pay-action callback response when the routes key is absent, raising:

LnurlResponseException: Expected Success or Error response. But no 'status' given.

(Related to lnbits/lnbits#3851)

Expected behaviour

The response is parsed and returned as a LnurlPayActionResponse with routes defaulting to [].

Actual behaviour

from_dict falls through to the status-handling branch and raises:

LnurlResponseException: Expected Success or Error response. But no 'status' given.

Root cause

is_pay_action_response requires both "pr" and "routes" to be present:

def is_pay_action_response(data: dict) -> bool:
    return "pr" in data and "routes" in data

LUD-06 specifies routes as an empty array in the success form, but many real-world implementations omit it entirely. The presence of "pr" alone is the correct signal for a pay-action callback.

LnurlPayActionResponse already defines routes with a safe default (routes: list[list[LnurlPayRouteHop]] = []), so parsing a response without routes is safe.

[dni]

LUD-06 specifies routes as an empty array in the success form, but many real-world implementations omit it entirely.

which makes them not compliant to the spec, i read 06 again nothing indicates that routes is optional.