Choice/Discover-into-hand fanfares add a candidates-only token to hand; the
chosen cardId rides keyAction.selectCard on the generating play, not the
orderList add op. Record idx->chosenCardId at generation (candidate-membership
join) so the later play reveals the real identity via the existing
BuildPlayedCard path; forward {type,cardId} to the opponent and strip
selectCard for hidden (open:0) picks (pass through for open:1, provisional).
- KnownListBuilder.MineChoicePicks + StripKeyActionForOpponent (pure)
- BattleSessionState.RecordChoicePicksFrom (reuses IdxToCardId, no new state)
- PlayActionsBroadcastBody.keyAction + KeyActionEntry/SelectCardEntry
- PlayActionsHandler wires both; EchoHandler unchanged (picks ride the send)
Tests (TDD red->green): 8 KnownListBuilder + 2 dispatch + 2 conformance
(shape-locked to tk2_regular L151 generation / L193 reveal). Full suite 976/0.
Spec: docs/superpowers/specs/2026-06-04-battle-node-choice-token-reveal-design.md
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
SVSim.BattleNode
Socket.IO node-server emulation for in-battle real-time traffic — the second of prod's 4-server
topology. Handles Matched / BattleStart / Deal / per-action PlayActions / Echo /
TurnEnd between a client and a server-side opponent, for TK2 PvP and AI rank battles.
Documentation lives in the outer repo
This project's canonical reference is a single hub doc in the outer SVSim repo (this directory is an inner git repo, so the doc isn't tracked alongside the code):
→ docs/battle-node.md (from the SVSim root) — architecture, the dispatch matrix by battle
type, connect handshake + crypto, BattleFinish wire-result semantics, SIO/EIO event coverage,
reliability (pubSeq/playSeq/Gungnir), wire-format gotchas, where-to-extend, the manual smoke
walkthrough, and the consolidated open-items list.
Relative path from here: ../../../docs/battle-node.md.
Detailed per-URI wire shapes are in docs/api-spec/in-battle/; the hub links into them.
Keep docs/battle-node.md updated in the same change whenever you alter node behavior.