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.

ui/src/lib/mock/client.ts

@@ -408,10 +408,9 @@ export class MockGateway implements GatewayClient {
       seat: this.mySeat(g),
       rack: [...g.rack],
       bagLen: g.bagLen,
-      // g.hintsRemaining is the per-game allowance; the wallet is the shared profile balance.
-      // hints_remaining folds the two together (as the backend does), walletBalance is the wallet.
-      hintsRemaining: g.hintsRemaining + this.profile.hintBalance,
-      walletBalance: this.profile.hintBalance,
+      // hintsRemaining is the per-game allowance alone; the wallet lives on the profile and the
+      // client adds it (lib/hints).
+      hintsRemaining: g.hintsRemaining,
     };
   }
 
@@ -530,7 +529,7 @@ export class MockGateway implements GatewayClient {
         score: valueForLetter(g.view.variant, letter),
         total: 0,
       },
-      hintsRemaining: g.hintsRemaining + this.profile.hintBalance,
+      hintsRemaining: g.hintsRemaining,
       walletBalance: this.profile.hintBalance,
     };
   }