feedback7 G-SMALL: co-op rooms can make AI teammates draft last (PR #368 by @anAtheist987)

Applied the host-only room option 「AI 队友最后选择」, default off. Off, the draft order and the random streams stay as they are. On, humans draft before AI seats after the existing shuffle, and a skip stays ahead of the AI seats.

Dropped docs/history/0.2.2.md and every §27 citation. The player-facing sentence is in docs/PLAYING.md. The room-option rule is in docs/design/match.md, docs/design/client.md and docs/design/network.md. The #338 per-bot faction and ban presets are not included.

Tests: node --test test/lobby-ai-last.test.js test/match/ai-picks-last.test.js test/ui/ai-picks-last.test.js — 18 pass. node --test test/lobby.test.js test/client-static.test.js — 378 pass. node tools/i18n.mjs check --all --strict — 1032/1032 in en, ja, ko and zh-TW, 0 errors.

public/css/screens/room.css

@@ -296,6 +296,13 @@
 }
 .dpick__opt.is-active .icon { opacity: 1; filter: drop-shadow(0 0 5px var(--d-color)); }
 .dpick--ro { border: 0; background: none; gap: .18rem; align-items: center; font-size: .14rem; }
+/* 「AI 队友最后选择」 (GitHub #338, co-op): one switch styled like a difficulty option, under the difficulty picker */
+.room-bar__opts { display: flex; flex-direction: column; align-items: flex-start; gap: .08rem; min-width: 0; }
+.ailast { display: flex; align-items: center; gap: .12rem; font-size: .14rem; }
+.ailast__opt { --d-color: var(--mint-400); height: .36rem; padding: 0 .14rem; border: 1px solid var(--line-2); background: rgba(0, 0, 0, .3); font-size: .15rem; letter-spacing: .04em; }
+.ailast__opt:last-child { border-right: 1px solid var(--line-2); }
+.ailast__opt .icon { opacity: .25; }
+.ailast__opt .icon.is-on { opacity: 1; }
 
 .ready-count[hidden] { display: none; }
 .ready-count { display: flex; align-items: baseline; gap: .06rem; font-size: .16rem; }