v2.2.5

Full Changelog: v2.2.1...v2.2.5

v2.2.5

Fixed: illegal move after promoting a pawn

Since v2.2.1 the bot sends the engine the full move history so that it
can avoid repetition draws. When the bot promoted a pawn, that history
could record the move without the promotion piece. The engine then
skipped the rest of the history, tried to promote the same pawn again,
FICS rejected the move, and the bot lost on time.

• The promotion piece is now read from the board after the move, so it
  is always included in the history.
• New safeguard: if FICS ever rejects one of the bot's moves, the bot
  searches again from the current position instead of waiting for its
  clock to run out. It does this once per move.

New: TCP keepalive and automatic reconnect

For players on unreliable connections.

• Keepalive: after 30 seconds without traffic, the connection is
  probed every 10 seconds. This stops home routers from silently
  dropping a quiet connection, and a dead connection is detected in
  about a minute instead of hours. The probes are invisible to FICS and
  to you.
• Automatic reconnect: if the connection drops, the bot no longer
  exits. It reconnects and logs back in, retrying after 5s, 10s, 30s
  and then every 60s. The status bar and console show each attempt,
  and quit still works while it is waiting.
• Resuming games: if the bot was in a game, FICS adjourns it. After
  reconnecting, the bot asks the opponent to resume. The moves played
  before the drop are not included in the saved PGN; recording restarts
  from the resumed position.

Improved: score graph scale

The score graph used to stop at ±10 pawns. Its scale now grows with
the evaluations (±1, ±2, ±5, ±10, ±20, ±50, ±100, …), so a large
advantage is no longer flattened against the top edge. Forced mates,
including engines that report a mate as a huge number such as
+7999.81, are drawn on the edge so they don't squash the rest of the
graph. Hover a point to see its exact score.

Other

• Release builds are faster to compile (thin LTO), and there is a new
  quick build profile for testing: cargo build --profile quick.
• The README now covers all current features, including the new
  "Playing a game" and "Flaky connections" sections.