Bump payjoin version to 1.0.0-rc.4

[spacebear21]

Prepares the payjoin-1.0.0-rc.4 release. Part of #1720.

Changelog

1.0.0-rc.4

This release locks down the public API ahead of the 1.0 freeze. It insulates the bitcoin-ohttp and bitcoin-hpke types from the public interface, marks public enums non_exhaustive and persistence transition types must_use, exposes transient versus fatal classification on PersistedError, corrects the create_error_request return type, renames the Receiver check methods, and removes utxos_to_be_locked. It also hardens the receiver against panic paths and fixes bugs in output substitution change handling, session replay, and coin selection.

Selected Improvements:

API Stabilization

• Insulate bitcoin-ohttp and bitcoin-hpke from the public API (Insulate bitcoin-ohttp and bitcoin-hpke from the public API #1702)
• Apply 1.0 freeze-required API fixes: #[non_exhaustive] enums, ShortIdError, OutputSubstitution export, and #[must_use] transition types (Apply 1.0 freeze-required API fixes (non_exhaustive, ShortIdError, OutputSubstitution, must_use) #1703)
• Expose transient versus fatal classification on PersistedError and return current state in transient errors (Return current state in transient errors #1724)
• Correct create_error_request return type (Correct create_error_request return type #1715)
• Rename Receiver<Monitor> check methods (check_for_broadcast to check_for_transaction) (Rename Monitor method #1661, Rename Receiver<Monitor>::check_for_broadcast to check_for_transaction, etc. #1684)
• Remove utxos_to_be_locked (Remove utxos_to_be_locked #1719)
• Add InputPair::outpoint() accessor (Expose InputPair outpoint over FFI #1654)

Bug Fixes and Hardening

• Prevent receiver panic paths (Prevent receiver panic paths #1704)
• Fix output substitution change misdirect (Fix output substitution change misdirect #1685)
• Fix session replay reporting closed sessions as expired (Fix replayEventLog report closed session as expired. #1672)
• Fix try_preserving_privacy returning Empty when candidates exist (Fix try_preserving_privacy returning Empty when candidates exist #1629)
• Assert bech32 encoding is uppercase (Assert bech32 encoding is uppercase #1666)

Dependencies

• Update to bitcoind async client 0.14 (Update bitcoind async client 0.14 #1646)
• Downgrade transitive dependencies to match minimal direct dependencies (Downgrade transitive deps to match minimal direct deps #1640)

Testing and Documentation

• Add tests to catch mutants (Add tests to catch mutants #1622)
• Add spec-related consts for readability in tests (Add Spec related consts for better readability in tests #1699)
• Employ new fallback_tx method (Employ new fallback_tx method #1625)
• Fix check_payment docstring (Fix check_payment docstring #1626)
• Fix commented test assert (Fix commented test assert #1624)
• Attach --no-run to feature-gated test runs to ensure compilation (Attach --no-run to the feature gated test runs just to ensure compilation #1621)

---

Disclosure: co-authored by Claude Code

🤖 Generated with Claude Code

[coveralls]

Coverage Report for CI Build 29117879408

Coverage remained the same at 86.01%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	15876
Covered Lines:	13655
Line Coverage:	86.01%
Coverage Strength:	343.76 hits per line

---

💛 - Coveralls

[benalleng]

ACK b750f44

🚀