revert(payment): revert #141 single-node issuer over-query window

[jacderida]

Summary

Reverts PR #141 (fix(payment): verify single-node issuer closeness against over-query window), restoring the paid-quote issuer close-group check in src/payment/verifier.rs to the form left by #140:

• XOR-only local routing-table lookup (find_closest_nodes_local_by_distance_with_self)
• against the configured close_group_size
• no 2 * close_group_size over-query widening
• no local→network hybrid fallback

Why #139 needs no separate revert

The intent was to revert #139 and #141 while keeping #140. PR #139 (widen paid-quote issuer admission to close group + margin) was already fully superseded and reverted by #140 (use XOR-only local lookup for close-group verification): #140 removed the storage_admission_width import and restored the close_group_size width. No #139 residue remains in the tree (grep storage_admission_width src/payment/verifier.rs is empty), so reverting #141 alone yields the exact desired end state. #140 is kept intentionally.

Verification

• cargo build (debug) ✅
• cargo fmt --all -- --check ✅
• cargo clippy --all-features -- -D clippy::panic -D clippy::unwrap_used -D clippy::expect_used ✅

This reverts commit d797cb8.

🤖 Generated with Claude Code

[dirvine]

Hermes review for PR #143

Verdict: LGTM / no blockers found — safe to merge once the remaining matrix test jobs finish green.

I reviewed this as the revert of #141 while keeping #140 intact.

What I verified

• src/payment/verifier.rs now matches the fix(payment): use XOR-only local lookup for close-group verification #140 verifier state for the SNP issuer path.
• The single-node paid-quote issuer check is back to:
  • XOR-only local lookup: find_closest_nodes_local_by_distance_with_self(...)
  • strict close_group_size
  • no 2 * close_group_size widening
  • no local→network fallback for SNP issuer closeness
• fix(payment): widen paid-quote issuer admission to close group + margin #139 does not need a separate revert here: fix(payment): use XOR-only local lookup for close-group verification #140 had already removed the storage_admission_width issuer-margin behaviour from src/payment/verifier.rs.
• Remaining find_closest_nodes_network / over-query-width logic in the file is Merkle-candidate scoped, not the SNP issuer path.

Local checks

• git diff --exit-code c7dd88048cd54b21abfda588771102d4da7d217f..HEAD -- src/payment/verifier.rs — pass; verifier matches fix(payment): use XOR-only local lookup for close-group verification #140 state.
• cargo test -q payment::verifier --lib — 74 passed.
• git diff --check origin/rc-2026.6.2...HEAD — pass.

CI status when checked

Passing: build jobs, clippy, docs, format, security audit, no-logging test.
Still pending: macOS/Ubuntu/Windows full test jobs.

No code issues found; I would merge after those pending tests complete successfully.