msig cleanup

[n13]

From #409

Note: Not doing 4, 5 from #409

#	Severity	Finding	Fix Effort
1	HIGH	Weight undercharge: iter_prefix().count() not benchmarked; active_proposals unused	Easy -- use existing counter
2	MEDIUM	Redundant call size check (DRY)	Trivial -- delete 1 line
3	MEDIUM	Silent try_insert error on per-signer counter	Easy
6	LOW	Extra write for threshold=1 proposals	Easy
7	LOW	Triple access to Multisigs storage in propose	Moderate refactor
8	LOW	Misleading auto-cleanup docstring	Trivial
9	LOW	claim_deposits no signer check	Trivial

[n13]

GPT Codex PR Review: #410 msig cleanup

PR: Quantus-Network/chain#410

Scope Reviewed

• pallets/multisig/src/lib.rs
• Commits:
  • c58fd4019696f1e036fab2dd8ba122f931707e8d
  • 4047064ed91afeb63171b8319b5f17ba7949a591
  • 907e8853beb3323bb939dac0481bb6de19c644a8

Findings

High

• None.

Medium

• None.

Low

• Added missing negative test coverage for claim_deposits signer-gating:
  • claim_deposits_fails_for_non_signer in pallets/multisig/src/tests.rs
  • Verifies non-signer gets NotASigner and proposal/deposit state is unchanged.

Behavioral Review Notes

• propose now uses active_proposals instead of iterating storage for total proposal limit checks.
• Redundant call-size guard was removed while preserving early size-check behavior.
• Per-signer proposal counter insertion now propagates errors instead of ignoring them.
• Threshold-1 proposals are created as Approved directly and emit ProposalReadyToExecute.
• approve continues to allow approvals after Approved status (no regression to previously fixed behavior).
• claim_deposits now enforces signer access, matching the intended permission model.

Validation

• cargo test -p pallet-multisig
• Result: 39 passed, 0 failed.

Recommendation

• Approve.