feat: unify toast styles and add quest/milestone toast notifications

- Merge .codex-toast and .achievement-toast into a single .game-toast class
- Fix storyToast inner class names and replace <button> wrapper with <div>
- Add QuestCompleteToast and QuestFailedToast components
- Add MilestoneToast for prestige, transcendence, and apotheosis events
- Move shared toast container to gameLayout so all toasts stack in one column
- Wire quest detection in GameContext to store full Quest objects for toast names
- Trigger prestige toast from both auto-prestige and manual prestige panel

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

@@ -47,7 +47,7 @@ const CodexToastItem = ({
   }
 
   return (
-    <div className="codex-toast" onClick={handleClick}>
+    <div className="game-toast" onClick={handleClick}>
       <span className="toast-icon">{"📖"}</span>
       <div className="toast-content">
         <span className="toast-label">{"✨ Lore Unlocked!"}</span>
@@ -70,13 +70,13 @@ const CodexToast = (): JSX.Element | null => {
   }
 
   return (
-    <div className="achievement-toast-container">
+    <>
       {pendingEntryIds.map((id) => {
         return (
           <CodexToastItem entryId={id} key={id} onDismiss={dismissCodexEntry} />
         );
       })}
-    </div>
+    </>
   );
 };