docs(plan): defer in-game chat, add Phase 1 (Casual) implementation plan

- DECISIONS.md: in-game chat (player↔player and human↔Gemma) deferred
  indefinitely. Blind-mode chat is a side channel that defeats the
  moderator-vocabulary security boundary; chat with Gemma leaks belief
  state mid-game. Resolvable but expensive — revisit only on demand.
- Spec: same deferral noted in "Out of scope".
- New plan: docs/superpowers/plans/2026-04-28-ai-player-phase-1-casual.md
  — 13 tasks, 80 sub-steps. Phase 1 only (Casual bot end-to-end). Phase 2
  (Recon) gets its own plan once Phase 1 outcomes inform Recon's target.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

DECISIONS.md

@@ -89,3 +89,4 @@ Spec: `docs/superpowers/specs/2026-04-28-ai-player-design.md`. All decisions bel
 - 2026-04-28: **AI vs AI public spectate-able games** — rejected for MVP. Self-play harness is CLI-only (`scripts/selfplay.ts`).
 - 2026-04-28: **Per-turn context compaction** — deferred. Spec uses `num_ctx: 32768` which covers ~128 turns; longer games would overflow but are rare in casual play. Add running-summary compaction if seen in practice.
 - 2026-04-28: **Bot rating / Elo / personalities** — out of scope. Two named buttons, no scoreboard.
+- 2026-04-28: **In-game chat (player ↔ player and human ↔ Gemma)** — deferred indefinitely. Two failure modes drove the deferral: (1) blind-mode chat is a side channel that bypasses the moderator-vocabulary security boundary ("knight on c3, take it" defeats the entire view-filter architecture); (2) chatting with Gemma during play leaks the bot's belief state and undermines the post-game reasoning reveal. Resolvable but expensive (two-history split for Gemma, blind-mode mute or social-variant warnings, mobile UI real estate). Revisit only if users explicitly ask. The post-game reasoning reveal already covers most of the "see what Gemma was thinking" appeal without the leak surface.

docs/superpowers/specs/2026-04-28-ai-player-design.md

@@ -595,6 +595,7 @@ Collapsed by default on mobile. Casual games omit the section.
 - Persistent reasoning logs across game restart (would require SQLite per the existing deferred row).
 - Bot rating / Elo tracking across games.
 - Bot personalities / styles ("aggressive recon", "defensive recon").
+- In-game chat (player ↔ player or human ↔ Gemma). Considered 2026-04-28; deferred indefinitely. Player chat in blind mode is a side channel that bypasses the moderator-vocabulary security boundary; chat with Gemma leaks the bot's belief state and undermines the post-game reasoning reveal. See `DECISIONS.md` "Deferred / Rejected" for the full rationale.
 
 ## Appendix A — Module layout