feat(lobby): enter the game immediately and wait for the opponent inside it

Quick auto-match no longer waits on a separate screen: Enqueue opens a real game seating the caller with an empty opponent seat (new game status 'open') and the player enters it at once. A second human searching the same variant+rule joins that open game; otherwise a background reaper seats a robot after a 90s + random 0-90s wait, pushing a new in-app opponent_joined event that fills the opponent card and re-enables resign and chat in place.

Matchmaking state is now the open games in the database (the in-memory pool, lobby.poll and lobby.cancel are gone), serialised by a per-bucket advisory lock. While a game is open the starter may move on their turn, but resign, chat and nudge are refused; the lobby and opponent card show "searching for opponent".

Schema edited in the baseline (no prod data): 'open' status, nullable game_players.account_id for the empty seat, and a games.open_deadline_at stamp; jet code regenerated.

backend/internal/inttest/open_match_test.go

@@ -0,0 +1,254 @@
+//go:build integration
+
+package inttest
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"scrabble/backend/internal/engine"
+	"scrabble/backend/internal/game"
+	"scrabble/backend/internal/social"
+)
+
+// The open-game suite covers an auto-match game that a player enters immediately and
+// waits inside (status 'open', the opponent seat empty) until a human or a robot joins.
+
+// evenOpeningSeed returns an even seed (so OpenOrJoin seats the starter at seat 0, which
+// moves first) whose fresh two-player English opening rack has a legal move.
+func evenOpeningSeed(t *testing.T) int64 {
+	t.Helper()
+	for seed := int64(2); seed <= 400; seed += 2 {
+		g, err := engine.New(testRegistry, engine.Options{Variant: engine.VariantEnglish, Version: testDictVersion, Players: 2, Seed: seed})
+		if err != nil {
+			t.Fatalf("engine new: %v", err)
+		}
+		if _, ok := g.HintView(); ok {
+			return seed
+		}
+	}
+	t.Fatal("no even opening seed found")
+	return 0
+}
+
+// openParams are the casual auto-match settings with a pinned seed.
+func openParams(seed int64) game.CreateParams {
+	return game.CreateParams{
+		Variant:              engine.VariantEnglish,
+		TurnTimeout:          24 * time.Hour,
+		HintsAllowed:         true,
+		HintsPerPlayer:       1,
+		MultipleWordsPerTurn: true,
+		Seed:                 seed,
+	}
+}
+
+func openGame(t *testing.T, svc *game.Service, starter uuid.UUID, seed int64) game.Game {
+	t.Helper()
+	g, joined, err := svc.OpenOrJoin(context.Background(), starter, openParams(seed), time.Now().Add(time.Minute))
+	if err != nil {
+		t.Fatalf("open game: %v", err)
+	}
+	if joined || g.Status != game.StatusOpen {
+		t.Fatalf("opened game = (joined %v, status %q), want (false, open)", joined, g.Status)
+	}
+	return g
+}
+
+// TestOpenGameStarterMovesThenWaits checks the starter (seat 0) may move on their turn
+// while the game is open, after which it is the empty opponent seat's turn and the
+// starter just waits.
+func TestOpenGameStarterMovesThenWaits(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	seed := evenOpeningSeed(t)
+	g := openGame(t, svc, provisionAccount(t), seed)
+	starter := g.Seats[0].AccountID
+
+	hint, ok := newMirror(t, seed, 2).HintView()
+	if !ok || len(hint.Tiles) == 0 {
+		t.Fatal("no opening move for the seed")
+	}
+	res, err := svc.SubmitPlay(ctx, g.ID, starter, hint.Tiles)
+	if err != nil {
+		t.Fatalf("starter play while open: %v", err)
+	}
+	if res.Game.Status != game.StatusOpen {
+		t.Errorf("after the starter's move the game must stay open, got %q", res.Game.Status)
+	}
+	if res.Game.ToMove != 1 {
+		t.Errorf("after the starter's move it must be the empty seat's turn (to_move 1), got %d", res.Game.ToMove)
+	}
+	if _, err := svc.Pass(ctx, g.ID, starter); !errors.Is(err, game.ErrNotYourTurn) {
+		t.Fatalf("starter acting on the opponent's turn = %v, want ErrNotYourTurn", err)
+	}
+}
+
+// TestOpenGameStarterWaitsWhenOpponentMovesFirst checks that when the starter is seated
+// at seat 1 (odd seed), the still-empty seat 0 is to move, so the starter cannot act.
+func TestOpenGameStarterWaitsWhenOpponentMovesFirst(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	starter := provisionAccount(t)
+	g, _, err := svc.OpenOrJoin(ctx, starter, openParams(1), time.Now().Add(time.Minute))
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	if g.ToMove != 0 || g.Seats[0].AccountID != uuid.Nil {
+		t.Fatalf("odd-seed open game: to_move %d seat0 %s, want the empty seat 0 to move", g.ToMove, g.Seats[0].AccountID)
+	}
+	if _, err := svc.Pass(ctx, g.ID, starter); !errors.Is(err, game.ErrNotYourTurn) {
+		t.Fatalf("starter acting on the empty seat's turn = %v, want ErrNotYourTurn", err)
+	}
+}
+
+// TestOpenGameJoinAfterStarterMoved checks a second human joins an open game even after
+// the starter has already made their first move, landing on the board mid-opening and
+// able to act on their turn.
+func TestOpenGameJoinAfterStarterMoved(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	seed := evenOpeningSeed(t)
+	g := openGame(t, svc, provisionAccount(t), seed)
+	starter := g.Seats[0].AccountID
+
+	hint, ok := newMirror(t, seed, 2).HintView()
+	if !ok {
+		t.Fatal("no opening move")
+	}
+	if _, err := svc.SubmitPlay(ctx, g.ID, starter, hint.Tiles); err != nil {
+		t.Fatalf("starter play: %v", err)
+	}
+
+	joiner := provisionAccount(t)
+	g2, joined, err := svc.OpenOrJoin(ctx, joiner, openParams(0), time.Now().Add(time.Minute))
+	if err != nil {
+		t.Fatalf("join: %v", err)
+	}
+	if !joined || g2.ID != g.ID {
+		t.Fatalf("join = (joined %v, game %s), want it to join %s", joined, g2.ID, g.ID)
+	}
+	if g2.Status != game.StatusActive || g2.MoveCount != 1 || g2.ToMove != 1 {
+		t.Fatalf("joined game = (status %q, moves %d, to_move %d), want (active, 1, 1)", g2.Status, g2.MoveCount, g2.ToMove)
+	}
+	// It is the joiner's turn (seat 1); they can act.
+	if _, err := svc.Pass(ctx, g.ID, joiner); err != nil {
+		t.Fatalf("joiner pass on their turn: %v", err)
+	}
+}
+
+// TestOpenGameResignRejectedUntilOpponent checks resign is refused while the game is
+// open and allowed once an opponent (a robot here) has joined.
+func TestOpenGameResignRejectedUntilOpponent(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	robots := newRobotService(t, svc)
+	if err := robots.EnsurePool(ctx); err != nil {
+		t.Fatalf("ensure pool: %v", err)
+	}
+	g := openGame(t, svc, provisionAccount(t), evenOpeningSeed(t))
+	starter := g.Seats[0].AccountID
+
+	if _, err := svc.Resign(ctx, g.ID, starter); !errors.Is(err, game.ErrNoOpponentYet) {
+		t.Fatalf("resign while open = %v, want ErrNoOpponentYet", err)
+	}
+
+	robotID, err := robots.Pick(engine.VariantEnglish)
+	if err != nil {
+		t.Fatalf("pick: %v", err)
+	}
+	if _, attached, err := svc.AttachRobot(ctx, g.ID, robotID); err != nil || !attached {
+		t.Fatalf("attach robot = (attached %v, err %v), want attached", attached, err)
+	}
+	res, err := svc.Resign(ctx, g.ID, starter)
+	if err != nil {
+		t.Fatalf("resign after the opponent joined: %v", err)
+	}
+	if res.Game.Status != game.StatusFinished {
+		t.Errorf("resign must finish the game, got %q", res.Game.Status)
+	}
+}
+
+// TestOpenGameChatAndNudgeRejected checks chat and nudge are refused while the game is
+// open (no opponent to converse with).
+func TestOpenGameChatAndNudgeRejected(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	soc := newSocialService()
+	g := openGame(t, svc, provisionAccount(t), evenOpeningSeed(t))
+	starter := g.Seats[0].AccountID
+
+	if _, err := soc.PostMessage(ctx, g.ID, starter, "hello", ""); !errors.Is(err, social.ErrGameNotActive) {
+		t.Errorf("chat while open = %v, want ErrGameNotActive", err)
+	}
+	if _, err := soc.Nudge(ctx, g.ID, starter); !errors.Is(err, social.ErrGameNotActive) {
+		t.Errorf("nudge while open = %v, want ErrGameNotActive", err)
+	}
+}
+
+// TestOpenGameSweeperSkips checks the turn-timeout sweeper never finishes an open game,
+// even with a long-stale turn clock (its seat is the empty opponent's).
+func TestOpenGameSweeperSkips(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	g := openGame(t, svc, provisionAccount(t), evenOpeningSeed(t))
+
+	setTurnStarted(t, g.ID, time.Now().Add(-1000*time.Hour))
+	if _, err := svc.SweepTimeouts(ctx, time.Now()); err != nil {
+		t.Fatalf("sweep: %v", err)
+	}
+	g2, err := svc.GameByID(ctx, g.ID)
+	if err != nil {
+		t.Fatalf("get game: %v", err)
+	}
+	if g2.Status != game.StatusOpen {
+		t.Errorf("open game must survive the sweeper, got %q", g2.Status)
+	}
+}
+
+// TestOpenGameLobbyShowsEmptySeat checks an open game appears in the starter's lobby
+// with two seats, one of them the still-empty opponent (uuid.Nil).
+func TestOpenGameLobbyShowsEmptySeat(t *testing.T) {
+	ctx := context.Background()
+	clearOpenGames(t)
+	svc := newGameService()
+	starter := provisionAccount(t)
+	g := openGame(t, svc, starter, evenOpeningSeed(t))
+
+	games, err := svc.ListForAccount(ctx, starter)
+	if err != nil {
+		t.Fatalf("list for account: %v", err)
+	}
+	var found *game.Game
+	for i := range games {
+		if games[i].ID == g.ID {
+			found = &games[i]
+			break
+		}
+	}
+	if found == nil {
+		t.Fatal("open game must appear in the starter's lobby")
+	}
+	var hasStarter, hasEmpty bool
+	for _, s := range found.Seats {
+		switch s.AccountID {
+		case starter:
+			hasStarter = true
+		case uuid.Nil:
+			hasEmpty = true
+		}
+	}
+	if len(found.Seats) != 2 || !hasStarter || !hasEmpty {
+		t.Errorf("open game seats = %+v, want the starter and one empty (nil) seat", found.Seats)
+	}
+}