fix: apply boss bounty runestones to local client state immediately

Without this, the client would auto-save stale state (runestones: 0)
after a first-kill bounty, causing the server's validateAndSanitize to
overwrite the correctly-persisted DB value back to zero.

apps/web/src/context/GameContext.tsx

@@ -463,6 +463,12 @@ export const GameProvider = ({ children }: { children: React.ReactNode }): React
                   crystals: prev.resources.crystals + result.rewards.crystals,
                 }
               : prev.resources,
+            prestige: result.rewards?.bountyRunestones
+              ? {
+                  ...prev.prestige,
+                  runestones: prev.prestige.runestones + result.rewards.bountyRunestones,
+                }
+              : prev.prestige,
             player: result.rewards
               ? {
                   ...prev.player,