- _get_level_hashes: remove (0x1F << parent_shift) from range_end so
bitmap only includes children of the actual parent prefix (not all
parents). Add level 0 virtual root that queries all level-1 entries.
- merkle_sync_start: send HASHES at level 0 (virtual root) instead of
level 1/prefix 0. Root-level REQUEST prefix reconstruction now uses
the correct level-1 prefix from DB.
- _handle_batch: use merkle_sync_prefix_bytes(next_lvl) for synthetic
child HASHES instead of current level's pb_i (could be wrong size).
- Remove timeout/retry mechanism: delete _session_timeout_cb,
_session_start_timer, timer/retries fields. ETCP provides reliable
transport — no need for application-layer retries.
Evgeny
be10714972