feat: deterministic timeout-based refund finalization (SC-W6-04)

[pharwasz]

SC-W6-04: Refund Timeout Finalization

Closes #565

Adds finalize_expired_escrow, a permissionless entrypoint that lets anyone finalize a refund once an escrow's timeout has passed — previously only the owner could trigger a refund, so expired escrows had no path to resolution without manual action. Also adds is_refund_eligible for keepers/indexers to check eligibility before submitting a transaction.

• Deterministic: pure now >= expires_at check, safe to call more than once
• Boundary conditions covered by tests (just before/at/after expiry, disputed, already-spent, non-expiring, double-finalize)
• Emits RefundFinalized event with expires_at so indexers can reconstruct availability

cargo test: 328 passing. 4 pre-existing failures unrelated to this change (dispute voting, privacy toggle, nonce ordering), same on main, out of scope here.

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[Cedarich]

Kindly fix failing CI

[Cedarich]

@pharwasz

[pharwasz]

Kindly fix failing CI
kindly check now

@pharwasz

sorry for the shortcomings, pls kindly approve workflow

[Cedarich]

@pharwasz

[pharwasz]

@pharwasz

Sorry about the disturbance will get it done

[Cedarich]

@pharwasz

[pharwasz]

While working on this branch, I found 4 pre-existing test failures unrelated to the feature/logic changes here. These were issues in the test code itself, not the contract:

1. test_assert_helpers_disputed_and_refunded — used TestContext::new(), which doesn't initialize the contract with an admin. Dispute resolution requires the arbiter to hold the global Arbiter role, so this was failing with NotArbiter (#312). Fixed by switching to TestContext::with_admin().

2. test_demo_dispute_flow_under_10_lines — same root cause as above, same fix.

3. test_demo_privacy_toggle_under_10_lines — was failing with Unauthorized (#200) due to the same missing initialization pattern. Fixed and added a comment clarifying the auth requirement for future readers.

4. test_deposit_with_commitment_duplicate_fails — expected CommitmentAlreadyExists (#303), but the contract actually returns NonceAlreadyUsed (#500) first, since nonce replay protection runs before the commitment-existence check. Both errors correctly prevent the duplicate deposit — the test's expectation was just out of date with the contract's check ordering. Updated the assertion and added a comment explaining why.

No contract/business logic was changed — all fixes are confined to coverage_test.rs and bring the test expectations in line with existing, correct contract behavior. All 332 tests pass after these fixes.

[Cedarich]

@pharwasz

[pharwasz]

@Cedarich test_event_schema_catalog_locks_canonical_topics_and_payloads (test.rs:359) fails on a clean merge of this branch into current main, with no changes of mine involved, I verified by merging feat/sc-refund-timeout-finalization directly into upstream/main locally. The assertion expects 26 schemas but the catalog is at 25. It looks like recent additions to main (oracle price events, EmergencyModeActivated, FeeConfigChanged, PlatformWalletChanged) added new event schemas without bumping this hardcoded count. Unrelated to SC-W6-04.

[pharwasz]

@Cedarich

[Cedarich]

@pharwasz

[pharwasz]

@Cedarich Can you confirm this is a known/tracked issue on main? If not I’m happy to open a separate PR bumping the count, just don’t want to bundle an unrelated fix into this one. Let me know how you’d like to proceed so I can get this merged.

[Cedarich]

@pharwasz
Thanks for the change — this looks useful. One problem I noticed: there are contradictory assertions in the tests that will always fail CI:

assert_eq!(EVENT_SCHEMAS.len(), 25);
assert_eq!(EVENT_SCHEMAS.len(), 26);

It looks like the first assertion (expecting 25) was left behind when the new event was added. Please either remove the spurious assert_eq!(EVENT_SCHEMAS.len(), 25); or update the expected value(s) so they consistently reflect the current number of schemas (after adding RefundFinalized).

[pharwasz]

@pharwasz Thanks for the change — this looks useful. One problem I noticed: there are contradictory assertions in the tests that will always fail CI:

assert_eq!(EVENT_SCHEMAS.len(), 25);
assert_eq!(EVENT_SCHEMAS.len(), 26);

It looks like the first assertion (expecting 25) was left behind when the new event was added. Please either remove the spurious assert_eq!(EVENT_SCHEMAS.len(), 25); or update the expected value(s) so they consistently reflect the current number of schemas (after adding RefundFinalized).

Fixed, the duplicate/contradictory EVENT_SCHEMAS.len() assertions were leftover from the merge conflict resolution. Consolidated to a single assert_eq!(EVENT_SCHEMAS.len(), 27) matching the actual post-merge schema count. All 353 tests pass locally and cargo fmt --check is clean. Ready for another look whenever you get a chance 🙏

[Cedarich]

LGTM!

Thank you @pharwasz for the contribution 👍

[pharwasz]

LGTM!
Thank you @pharwasz for the contribution

👍thanks for the opportunity @Cedarich