feat(discovery-core): add incoming state sync orchestrator

[m-kus]

TL;DR

Added a new sync module with an orchestrator for incoming state discovery that efficiently processes channels, subchannels, and notes.

What changed?

• Created a new sync module in the discovery-core crate
• Implemented incoming_state.rs with a hierarchical discovery system that:
  • Discovers incoming channels, subchannels, and notes in a coordinated way
  • Uses cursor-based pagination to handle large datasets efficiently
  • Processes channels and subchannels concurrently using FuturesUnordered
  • Tracks completion state to avoid redundant work
• Added comprehensive tests that verify pagination behavior with precise budget control

---

This change is 

[m-kus]

• feat(e2e): starknet integration demo explorer #467 : 3 dependent PRs (#480 , #502 , #512 )
• feat(discovery-service): add fallback for chain state, e2e test in the starknet integration environment #466
• feat(e2e): add indexer e2e test suite with sdk devnet helpers #486
• feat(sdk): add indexer discovery provider #485
• feat(discovery-service): add preflight check endpoint #484
• feat(discovery-service): add outgoing state sync endpoint #483
• feat(discovery-service): add incoming sync endpoint with validation and error handling #482
• feat(discovery-service): centralize configuration into config module #481
• feat(discovery-core): add transfer preflight check #474
• feat(discovery-core): add outgoing state sync orchestrator #473
• feat(discovery-core): add incoming state sync orchestrator #472 👈 (View in Graphite)
• feat(discovery-core): add paginated last-note-index search with bisection #471
• feat(discovery-core): add paginated outgoing channel discovery #470
• refactor: propagate compliance-to-auditor rename and fee params to sdk and rust #505
• main

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[Yoni-Starkware]

@Yoni-Starkware reviewed 4 files and all commit messages, and made 3 comments.
Reviewable status: 4 of 5 files reviewed, 3 unresolved discussions (waiting on m-kus).

---

crates/discovery-core/src/sync/incoming_state.rs line 91 at r2 (raw file):

    // On a fresh cursor this is vacuously true; on subsequent calls it fires
    // once all previously discovered channels have been fully processed.
    let channels = if cursor.all_channels_processed() {

Suggestion:

 let new_channels = 

---

crates/discovery-core/src/sync/incoming_state.rs line 115 at r2 (raw file):

    }

    let mut subchannels: Vec<IncomingSubchannel> = Vec::new();

Suggestion:

    let mut new_subchannels: Vec<IncomingSubchannel> = Vec::new();

---

crates/discovery-core/src/sync/incoming_state.rs line 211 at r2 (raw file):

            note.token = token;
            notes.push(note);
        }

For sanity, please check that they both were zeros before.
Or, have two structs - with and without these two fields

Code quote:

        // Enrich notes with sender and token context.
        for mut note in new_notes {
            note.sender_addr = sender_addr;
            note.token = token;
            notes.push(note);
        }

[Yoni-Starkware]

@Yoni-Starkware reviewed 1 file and made 1 comment.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on m-kus).

[m-kus]

@m-kus resolved 3 discussions.
Reviewable status: 4 of 6 files reviewed, all discussions resolved (waiting on Yoni-Starkware).

[Yoni-Starkware]

@Yoni-Starkware reviewed 2 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on m-kus).