refactor: simplifying storage by giving it to the client directly

[SimonRastikian]

Simplifies the triple generation part following #3164. Concretely, it refactors TripleStorage::new so the storage takes the network client directly, instead of being handed the two pieces of state it used to derive from that client.

Net effect: TripleStorage depends on one cohesive object (the mesh client) rather than being passed several client-derived values separately.

Reference #1680 (comment)

[claude]

Pull request overview

Refactors TripleStorage::new to accept a &Arc<MeshNetworkClient> in place of two client-derived arguments (my_participant_id and an alive_participant_ids_query closure). This aligns TripleStorage::new's signature with PresignatureStorage::new, which already takes the client directly, and centralizes the "who is alive?" closure construction inside the storage constructor via the shared active_participants_query helper.

Changes:

• TripleStorage::new now takes &Arc<MeshNetworkClient> and internally derives my_participant_id() and calls active_participants_query(client) (crates/node/src/providers/ecdsa/triple.rs:57)
• EcdsaSignatureProvider::new simplified: no longer builds the alive-query closure at the call site (crates/node/src/providers/ecdsa.rs:70)
• New test-only helper network::testing::new_test_client constructs a fully-alive MeshNetworkClient for unit tests (crates/node/src/network.rs:952)
• Three cleanup tests and the local new_triple_store helper migrated to the new signature via new_test_client

Reviewed changes

Per-file summary

File	Description
crates/node/src/providers/ecdsa/triple.rs	New TripleStorage::new signature; new_triple_store test helper uses new_test_client
crates/node/src/providers/ecdsa.rs	Call site simplified to pass &client
crates/node/src/network.rs	Adds new_test_client helper in the testing module
crates/node/src/assets/cleanup.rs	Three cleanup tests rewired to construct the store from new_test_client

Findings

No blocking issues. Purely mechanical refactor with no behavior change:

• active_participants_query(client) reproduces the exact closure previously built inline (client.all_alive_participant_ids()), so runtime behavior is preserved.
• All prior test call sites passed all_participants as the "alive" list, which matches the new new_test_client behavior (TestConnectivityInterface::is_bidirectionally_connected() returns true and indexer heights all start at 0, so every participant appears alive).
• MeshNetworkClient::new is private, but network::testing is a submodule of network, so super::MeshNetworkClient::new remains accessible.
• Matches the existing PresignatureStorage::new idiom (crates/node/src/providers/ecdsa_common.rs:46), improving consistency.

Non-blocking (nits, optional):

• crates/node/src/network.rs:952 — new_test_client duplicates ~5 lines of the transport/tracker plumbing that already appears in new_test_transports and new_task_channel_for_test. Not worth extracting on its own, but if a fourth variant appears, consolidating into a single TestMeshTransportSender/IndexerHeightTracker builder would pay off.

✅ Approved