feat(cardshed): attack + defense + phase transitions (M7+M8+M9)

[w7-mgfcode]

Sub-issue of #146. PRP 3 milestones M7 (AttackSelect / S05) + M8 (DefenseSelect / S06) + M9 (Phase transitions + TurnState wiring). Reference: `PRPs/cardshed-03-experience-prp.md` lines 844–913.

Scope

M7 — AttackSelect

• `docs/SCREENS/attack-select.md` (Stitch)
• `apps/ui/src/features/table/AttackSelect.tsx` — uses `getLegalActions(state, attackerId)` to highlight playable cards; selecting calls `validateAttack(selected, hand)` to enable/disable Send
• Dispatch `{ kind: "Attack", playerId, cardIds }`

M8 — DefenseSelect

• `docs/SCREENS/defense-select.md` (Stitch)
• `apps/ui/src/features/table/DefenseSelect.tsx` + `components/{PendingAttackPanel,BeatPairButton}.tsx`
• For each unbeaten attack, on hover highlight counter cards where `canBeat(attack, counter, trump) === true`
• Dispatch `{ kind: "Beat", ... }` and `{ kind: "Stop", ... }` (with confirm when partial)

M9 — Phase transitions

• `apps/ui/src/components/PhaseTransitionOverlay.tsx` — render the 6 `TurnState` values with distinct affordances; aria-live polite for screen readers

Acceptance

• `Skill: stitch-design` → both screens committed
• AttackSelect: 0/2/4/6 cards → Send disabled with `ATTACK_INVALID_SIZE` tooltip
• AttackSelect: 3 = pair+kicker → Send enabled; 5 with quad → DISABLED with `ATTACK_NO_TWO_PAIRS`
• Rejection messages quote core's `ValidationError.code` verbatim — no re-implementation of `validateAttack`
• DefenseSelect: counter that can't beat → `BEAT_ILLEGAL` disabled state
• Stop button shows Radix Tooltip + requires confirm when `unbeatenCards.length > 0`
• After all beats, phase → `Resolving` and Stop is promoted (counter-attack hint) — see contradiction T10 — Catalog UI + detail view + MCP + E2E dogfood #10
• PhaseTransitionOverlay renders `Dealing → AwaitingAttack → AwaitingDefense → Resolving → RoundEnded → MatchEnded` distinctly
• aria-live polite announcements for every transition
• `agent-browser` captures `dogfood-output//{m7-attack,m8-defense,m9-phases}/`

Common bugs (from PRP 3)

• Re-implementing `validateAttack` or `canBeat` in the UI (FORBIDDEN — import + call)
• Submitting on Enter without explicit confirm — allow mis-clicks
• Allowing Stop without confirm at partial-defence point — destructive
• Missing the `Resolving` branch (contradiction T10 — Catalog UI + detail view + MCP + E2E dogfood #10)
• Blocking input during transition without a timeout — soft-lock risk

Complexity

M + M + S = ~10–15 hours.