* Add BIP 157 compact block filter chain source

* Add CBF integration tests and documentation

* Add optional fee source from esplora/electrum

Fixes the problem when the funding tx is not registered for CBF node, for
example during splicing.

Added macros to skip incompatible with CBF backend tests (which require
mempool).

* Remove race condition in test unified_send_receive

Decrease timeouts to not falsely conclude some tests as passing

* Fix CBF chain source build errors and UniFFI bindings (#5)

* Remove last_synced_height from cbf

Previously we tracked synced height and also had dirty flag for rescan
which was made from the genesis block. This was removed in favor of
block heights from channel manager and onchain wallet.

Safety reorg interval of 7 blocks (look-back) is added.

Force tests use CBF config with 1 required peers, as otherwise it would
die if one of two required peers went offline (which made impossible
testing of scenarios with 2 nodes on which goes offline).

* feat(cbf):
  add auto-restart with exponential backoff (#10)

* refactor(cbf): extract build_cbf_node helper and add wallet reference
* feat(cbf): auto-restart bip157 node with exponential backoff
* feat(cbf): add liveness check before returning requester
* fix(cbf): clean up scan state on filter scan failure
* fix(cbf): add per-block-fetch timeout to wallet sync

* test(cbf): strengthen wait_for_cbf_sync with state verification

The old wait_for_cbf_sync only checked that the onchain sync timestamp
advanced, which could false-pass when the timestamp updated but wallet
state was still stale. The new version verifies both onchain and
lightning wallet syncs completed, and accepts a check closure so callers
can assert concrete wallet state (e.g. balance, payment existence).

Also simplifies CbfSyncConfig in test setup to use Default (which
already sets required_peers: 1 and reasonable timeouts).

* Add test to capture wallet checkpoint push problems

* fix(cbf): use CheckPoint::insert for reorg-aware wallet sync

`push` only appends above the tip, so when `recent_history` contained
blocks at or below the wallet's current checkpoint height after a reorg,
the stale hashes on the wallet checkpoint were never replaced. Switch to
`CheckPoint::insert`, which detects conflicting hashes and purges stale
blocks, matching bdk-kyoto's `UpdateBuilder::apply_chain_event`.

Also clear `latest_tip` on `BlockHeaderChanges::Reorganized` so cached
tip state does not point at an abandoned chain.

Update the `checkpoint_building_handles_reorg` unit test (added in
c1844b3) to exercise the fixed behaviour: a reorg where the new tip
is at the same height as the wallet's checkpoint must still result
in the reorged hashes winning.

Disclosure: drafted with assistance from Claude Code.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* remove latest_tip from the cbf chain source

* fix(cbf): advance lightning-wallet sync timestamp when no scripts registered

`sync_lightning_wallet` returned early without updating
`latest_lightning_wallet_sync_timestamp` when no scripts were registered,
causing `wait_for_cbf_sync` to hang on start/stop/reinit cycles. Fold the
empty-scripts branch into the main path so both share a single
`update_node_metrics_timestamp` site at the end of the closure.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix(cbf): treat UnknownHash as skip-this-cycle in fee_rate_cache_from_cbf

After a checkpoint-based resume, `requester.chain_tip()` can return the
checkpoint hash which has no `BlockNode` in kyoto's tree yet, causing
`get_block` to fail with `FetchBlockError::UnknownHash` and surfacing as
`FeerateEstimationUpdateFailed` from `node.start()`. Skip the cycle and
retry later instead of erroring.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* retrigger CI

* fix(cbf): update write_node_metrics to update_and_persist_node_metrics after upstream API change

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Yeji Han <yeji.hvn@gmail.com>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>