A reorganisation was neither recorded nor acted upon, and a competing header at the tip's
own height was ignored for as long as the tip stood, leaving the listener on an orphan.
- A header at the height we hold with a different hash is followed through the same
fork-point search as any other reorg (ELC-09) instead of being ignored; it still has to
bring valid work and a connected chain.
- ElectrumListener._record_reorg writes `chain_reorg_detected` (depth, fork height, old and
new tip height and hash) before the window moves, so a failed write ends the session and
the next server's announcement of the same fork is recorded then. Depth 1 is a
transaction of its own; depth >= 2 also pauses the lottery with paused_reason 'reorg'
and writes `lottery_paused` in the same transaction (begin_immediate first).
- Docs: ELC-09/22/23/24, AUD-03/11/38, DAT-30/69, OPS-30, RND-04, ADR-26/52 lose their
B-85 "da implementare" lines.
Tests changed because the spec changed: test_apply_header_ignores_a_competing_header_at_
the_current_tip_height encoded the B-64 behaviour that ELC-09 now reverses; it is replaced
by test_a_competing_header_at_the_tip_height_is_a_reorg_to_follow and the depth tests.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>