feat: add daily login bonus system with streak tracking

Awards escalating gold rewards each consecutive day (Day 7 grants bonus
crystals). Streak resets on missed days; a week multiplier boosts all
rewards for longer streaks. Shows a modal on first daily load and
displays the current streak on the character sheet.

apps/web/src/components/game/GameLayout.tsx

@@ -23,6 +23,7 @@ import { DailyChallengePanel } from "./DailyChallengePanel.js";
 import { ExplorationPanel } from "./ExplorationPanel.js";
 import { CharacterSheetPanel } from "./CharacterSheetPanel.js";
 import { CraftingPanel } from "./CraftingPanel.js";
+import { LoginBonusModal } from "./LoginBonusModal.js";
 
 type Tab = "adventurers" | "upgrades" | "quests" | "bosses" | "equipment" | "achievements" | "prestige" | "transcendence" | "apotheosis" | "statistics" | "daily" | "codex" | "about" | "exploration" | "crafting" | "character";
 
@@ -46,7 +47,7 @@ const BASE_TABS: { id: Tab; label: string }[] = [
 ];
 
 export const GameLayout = (): React.JSX.Element => {
-  const { state, isLoading, error, battleResult, dismissBattle, lastSavedAt, isSyncing, forceSync, newCodexEntryIds } = useGame();
+  const { state, isLoading, error, battleResult, dismissBattle, lastSavedAt, isSyncing, forceSync, newCodexEntryIds, loginBonus, dismissLoginBonus } = useGame();
   const [activeTab, setActiveTab] = useState<Tab>("adventurers");
   const [editingProfile, setEditingProfile] = useState(false);
 
@@ -87,6 +88,9 @@ export const GameLayout = (): React.JSX.Element => {
       <OfflineModal />
       <AchievementToast />
       <CodexToast />
+      {loginBonus && (
+        <LoginBonusModal bonus={loginBonus} onClose={dismissLoginBonus} />
+      )}
       {battleResult && (
         <BattleModal battle={battleResult} onDismiss={dismissBattle} />
       )}