feat:align async_order JSON types with rgb-lightning-node dev

[bandrivskiy]

fix(apay): align async_order JSON types with rgb-lightning-node dev

Summary

Align utexo-lsp with the current rgb-lightning-node dev branch for APay (Async Payments / Lightning Address): bump the submodule and fix JSON types on POST /internal/async_order/new so they match the RLN contract.

Problem

After moving rgb-lightning-node forward on dev, the async order contract changed:

• In the async_order.new response, accepted_through_index, next_index_expected, unused_hashes, and refill_batch_size are integers (per openapi.yaml), not strings.
• In requests from RLN, hash_index in the hash batch may be sent as a JSON number (1), not only as a string ("1").

The previous utexo-lsp code serialized those response fields as string and did not accept numeric hash_index, so the LSP JSON-RPC payload no longer matched what RLN expects/sends. That broke integration tests and recipient hash-pool bootstrap via async_order.new.

The submodule was pinned to 4e8c7f4 (an older dev), missing recent UTEXO changes (gossip, Dockerfile, RLN-side APay updates, etc.).

Changes

internal/lspapi/models.go

• AsyncOrderNewResponse: AcceptedThroughIndex, NextIndexExpected, UnusedHashes, RefillBatchSize are uint64 instead of string.
• AsyncOrderNewHashInput.UnmarshalJSON: accepts hash_index as either a string or a number (compatible with RLN serialization).

internal/lspapi/async_order.go

• asyncOrderSnapshotTx returns numeric fields in the JSON-RPC result (no strconv.FormatInt → string).

internal/lspapi/api_async_order_test.go

• Assertions updated for uint64.
• New test TestInternalAsyncOrderNewAcceptsNumericHashIndex for a batch with "hash_index": 1.

Submodule rgb-lightning-node

• 4e8c7f4 → 72b8d10 (UTEXO-Protocol/rgb-lightning-node@dev — adjust dockerfile and dockerignore #56).
• Includes the matching rust-lightning revision from that commit.

[txalkan]

Thank you, @bandrivskiy!
To fix the Python E2E test, please add lsp_base_url=None and lsp_bearer_token=None.