- 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
