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/hints.ts

@@ -1,28 +1,23 @@
 // Hint-count derivation, kept out of the .svelte component so it is unit-testable.
 //
-// The badge shows the per-game hint allowance remaining plus the player's global hint
-// wallet. The server's hints_remaining folds the two together, but the wallet is global —
-// shared across every game — so caching the combined number per game makes it go stale the
-// moment a wallet hint is spent in another game. We therefore split it: the per-game
-// allowance is hints_remaining - wallet_balance (both from the same fetch, so it is stable
-// and cacheable), and the wallet is read live from the global profile, never the per-game
-// snapshot.
+// The badge shows the per-game hint allowance remaining plus the player's global hint wallet. The
+// view's hints_remaining is the per-game allowance alone; the wallet is global (shared across every
+// game) and read live from the profile (payments), never the per-game snapshot — so a wallet hint
+// spent in another game stays reflected here.
 
 import type { StateView } from './model';
 
 /**
- * hintsLeft is the hint count for the badge: the per-game allowance remaining (the view's
- * hints_remaining minus the wallet snapshot baked into that same view) plus the live global
- * wallet balance. Passing the live wallet (not view.walletBalance) is what keeps the count
- * correct when a wallet hint was spent in another game since this view was fetched.
+ * hintsLeft is the hint count for the badge: the per-game allowance remaining (view.hintsRemaining)
+ * plus the live global wallet balance (passed in from the profile, so it stays correct when a wallet
+ * hint was spent in another game since this view was fetched).
  */
 export function hintsLeft(
-  view: Pick<StateView, 'hintsRemaining' | 'walletBalance'> | null,
+  view: Pick<StateView, 'hintsRemaining'> | null,
   walletBalance: number,
 ): number {
   if (!view) return 0;
-  const allowance = Math.max(0, view.hintsRemaining - view.walletBalance);
-  return allowance + Math.max(0, walletBalance);
+  return Math.max(0, view.hintsRemaining) + Math.max(0, walletBalance);
 }
 
 /** HINT_GATE_MS is the idle time a vs_ai player must be stuck on a turn before a hint unlocks. */