fix(game): show granted/bought hints in-game — finish the D31 wire removal

The in-game hint badge ignored the payments hint wallet: loading a game clobbered
app.profile.hintBalance with the deprecated StateView.wallet_balance (zeroed in the
D31 domain removal but left in the protocol as a dead 0, then synced over the real
balance at game load).

Finish the removal honestly. StateView carries the per-game allowance alone
(hints_remaining); the purchasable wallet lives solely on the profile and the client
adds it (lib/hints). Removed StateView.wallet_balance across every layer — backend
StateView/DTO, notify.PlayerState (live events), gateway StateResp + wire.StateView,
the client model/codec/mock/localgame — and dropped the now-unused wallet arg from
hintsRemaining. The FBS field is tombstoned `(deprecated)` (not deleted) so the vtable
slots after it stay stable across a rolling deploy; no accessor is generated. HintResult
keeps wallet_balance (the real post-spend payments balance the client adopts into the
profile). The StateView type no longer has walletBalance, so the clobber cannot return
without a compile error.

Tests: hintsRemaining (2-arg); hints.hintsLeft (allowance + live wallet, no strip); the
game state/hint integration (allowance-only HintsRemaining); gateway transcode; FBS regen.

backend/internal/game/eventwire.go

@@ -74,7 +74,6 @@ func playerState(v StateView, names []string, includeAlphabet bool) (notify.Play
 		Rack:           rack,
 		BagLen:         v.BagLen,
 		HintsRemaining: v.HintsRemaining,
-		WalletBalance:  v.WalletBalance,
 	}
 	if includeAlphabet {
 		tab, err := engine.AlphabetTable(v.Game.Variant)

backend/internal/game/helpers_test.go

@@ -55,16 +55,16 @@ func TestPayloadExchangeRoundTrip(t *testing.T) {
 }
 
 func TestHintsRemaining(t *testing.T) {
-	cases := []struct{ allowance, used, wallet, want int }{
-		{1, 0, 3, 4},
-		{1, 1, 3, 3},
-		{1, 2, 3, 3}, // used past allowance clamps to 0
-		{0, 0, 5, 5},
-		{2, 1, 0, 1},
+	cases := []struct{ allowance, used, want int }{
+		{1, 0, 1},
+		{1, 1, 0},
+		{1, 2, 0}, // used past allowance clamps to 0
+		{3, 1, 2},
+		{0, 0, 0},
 	}
 	for _, c := range cases {
-		if got := hintsRemaining(c.allowance, c.used, c.wallet); got != c.want {
-			t.Errorf("hintsRemaining(%d,%d,%d) = %d, want %d", c.allowance, c.used, c.wallet, got, c.want)
+		if got := hintsRemaining(c.allowance, c.used); got != c.want {
+			t.Errorf("hintsRemaining(%d,%d) = %d, want %d", c.allowance, c.used, got, c.want)
 		}
 	}
 }

backend/internal/game/service.go

@@ -1207,7 +1207,7 @@ func (svc *Service) Hint(ctx context.Context, gameID, accountID uuid.UUID) (Hint
 		return HintResult{}, err
 	}
 	used++
-	return HintResult{Move: move, HintsRemaining: hintsRemaining(pre.HintsPerPlayer, used, walletAfter), WalletBalance: walletAfter}, nil
+	return HintResult{Move: move, HintsRemaining: hintsRemaining(pre.HintsPerPlayer, used), WalletBalance: walletAfter}, nil
 }
 
 // Candidates returns the to-move player's legal plays for a seated player on
@@ -1290,11 +1290,9 @@ func (svc *Service) GameState(ctx context.Context, gameID, accountID uuid.UUID)
 		Seat:   seat,
 		Rack:   g.Hand(seat),
 		BagLen: g.BagLen(),
-		// The hint wallet moved to payments (svc.hintWallet); the deprecated accounts.hint_balance
-		// is no longer read, so the wire wallet is 0 and HintsRemaining is the per-seat allowance.
-		// The client adds the profile's payments hint balance on top (lib/hints.hintsLeft).
-		HintsRemaining: hintsRemaining(pre.HintsPerPlayer, pre.Seats[seat].HintsUsed, 0),
-		WalletBalance:  0,
+		// HintsRemaining is the per-seat allowance only; the purchasable wallet lives on the profile
+		// (payments) and the client adds it (lib/hints.hintsLeft).
+		HintsRemaining: hintsRemaining(pre.HintsPerPlayer, pre.Seats[seat].HintsUsed),
 		// vs_ai idle-hint gate (seconds left; 0 for a human game / first move / not your turn).
 		HintUnlockLeftSeconds: hintUnlockLeftSeconds(pre, seat, svc.clock()),
 	}, nil
@@ -1775,10 +1773,10 @@ func (svc *Service) DictBytes(variant engine.Variant, version string) ([]byte, e
 	return svc.registry.DictBytes(variant, version)
 }
 
-// hintsRemaining is a player's remaining hint budget: the unspent per-game
-// allowance plus the profile wallet.
-func hintsRemaining(allowance, used, wallet int) int {
-	return max(0, allowance-used) + wallet
+// hintsRemaining is the unspent per-game hint allowance. The purchasable wallet is separate,
+// carried on the profile (payments), and the client adds it (lib/hints.hintsLeft).
+func hintsRemaining(allowance, used int) int {
+	return max(0, allowance-used)
 }
 
 // allowedTimeout reports whether d is one of the offered move clocks.

backend/internal/game/types.go

@@ -211,10 +211,9 @@ type MoveResult struct {
 	BagLen int
 }
 
-// HintResult is a revealed hint and the requesting player's remaining hint
-// budget (per-seat allowance plus profile wallet) after spending one. WalletBalance is
-// the global wallet alone, so the client can keep its live wallet authoritative and
-// re-derive the per-game allowance (HintsRemaining - WalletBalance).
+// HintResult is a revealed hint with the per-seat allowance remaining (HintsRemaining) and the
+// purchasable hint wallet after spending one (WalletBalance, from payments). The client adopts
+// WalletBalance into the profile so the badge stays live across games (lib/hints).
 type HintResult struct {
 	Move           engine.MoveRecord
 	HintsRemaining int
@@ -241,9 +240,6 @@ type StateView struct {
 	Rack           []string
 	BagLen         int
 	HintsRemaining int
-	// WalletBalance is the player's global hint-wallet balance alone (HintsRemaining folds
-	// it in with the per-game allowance), so the client keeps the wallet live across games.
-	WalletBalance int
 	// HintUnlockLeftSeconds is, for a vs_ai game on the requesting player's turn, the seconds left
 	// until the idle hint unlocks (the robot's last move plus the idle window, from the server clock);
 	// 0 for the human's first move, when it is not their turn, or a non-vs_ai game. The vs_ai hint is

backend/internal/inttest/game_test.go

@@ -424,13 +424,13 @@ func TestHintPolicy(t *testing.T) {
 		t.Fatalf("first hint: %v", err)
 	}
 	// The allowance is spent before the wallet: with an empty wallet, the state now reports no
-	// hints left and a zero wallet, so the per-game allowance (HintsRemaining-WalletBalance) is 0.
+	// per-game allowance left (HintsRemaining is the allowance alone; the wallet lives on the profile).
 	st, err := svc.GameState(ctx, g.ID, seats[0])
 	if err != nil {
 		t.Fatalf("state: %v", err)
 	}
-	if st.HintsRemaining != 0 || st.WalletBalance != 0 {
-		t.Errorf("after allowance hint: hints=%d wallet=%d, want 0/0", st.HintsRemaining, st.WalletBalance)
+	if st.HintsRemaining != 0 {
+		t.Errorf("after allowance hint: hints=%d, want 0", st.HintsRemaining)
 	}
 	if _, err := svc.Hint(ctx, g.ID, seats[0]); !errors.Is(err, game.ErrNoHintsLeft) {
 		t.Fatalf("second hint = %v, want ErrNoHintsLeft", err)
@@ -444,9 +444,10 @@ func TestHintPolicy(t *testing.T) {
 	if err != nil {
 		t.Fatalf("wallet hint: %v", err)
 	}
-	// The allowance stays exhausted; the wallet dropped 2->1, and WalletBalance carries it alone.
-	if res.HintsRemaining != 1 || res.WalletBalance != 1 {
-		t.Errorf("wallet hint: hints=%d wallet=%d, want 1/1", res.HintsRemaining, res.WalletBalance)
+	// The allowance stays exhausted (HintsRemaining is the allowance alone, so 0); the wallet dropped
+	// 2->1 and WalletBalance carries it (the client adopts it into the profile).
+	if res.HintsRemaining != 0 || res.WalletBalance != 1 {
+		t.Errorf("wallet hint: hints=%d wallet=%d, want 0/1", res.HintsRemaining, res.WalletBalance)
 	}
 	// game_players.hints_used counts BOTH hints (1 allowance + 1 wallet) — the per-game total
 	// that feeds the player's lifetime hint statistics, not just the allowance.

backend/internal/notify/encode.go

@@ -83,7 +83,6 @@ func buildStateView(b *flatbuffers.Builder, s PlayerState) flatbuffers.UOffsetT
 		Rack:           s.Rack,
 		BagLen:         s.BagLen,
 		HintsRemaining: s.HintsRemaining,
-		WalletBalance:  s.WalletBalance,
 		Alphabet:       alphabet,
 	})
 }

backend/internal/notify/payload.go

@@ -56,7 +56,6 @@ type PlayerState struct {
 	Rack           []int
 	BagLen         int
 	HintsRemaining int
-	WalletBalance  int
 	Alphabet       []AlphabetLetter
 }
 

backend/internal/server/dto.go

@@ -177,7 +177,6 @@ type stateDTO struct {
 	Rack           []int   `json:"rack"`
 	BagLen         int     `json:"bag_len"`
 	HintsRemaining int     `json:"hints_remaining"`
-	WalletBalance  int     `json:"wallet_balance"`
 	// HintUnlockLeftSeconds is the vs_ai idle-hint gate: seconds until the hint unlocks (0 for a human
 	// game / first move / not your turn). The client anchors a monotonic countdown to it.
 	HintUnlockLeftSeconds int                `json:"hint_unlock_left_seconds"`
@@ -334,7 +333,6 @@ func stateDTOFrom(v game.StateView, includeAlphabet bool) (stateDTO, error) {
 		Rack:                  rack,
 		BagLen:                v.BagLen,
 		HintsRemaining:        v.HintsRemaining,
-		WalletBalance:         v.WalletBalance,
 		HintUnlockLeftSeconds: v.HintUnlockLeftSeconds,
 	}
 	if includeAlphabet {