feat: add main questline / overarching story system (#24)

- 22 chapters across the full game arc (18 zone bosses + 4 milestones)
- Choice-based narrative with {characterName} dynamic substitution
- Story progress (unlocked + completed chapters) is permanent across all resets
- Server-side anti-cheat: chapters/choices can only accumulate, never be removed
- Tab badge and lower-right toast notifications for newly unlocked chapters
- Story choices displayed on the Character Sheet and Character Page
- How to Play entry added to About panel

apps/api/src/services/apotheosis.ts

@@ -35,6 +35,8 @@ export const buildPostApotheosisState = (
     ...(currentState.codex ? { codex: currentState.codex } : {}),
     // Apotheosis data is eternal — never wiped by any reset
     apotheosis: newApotheosisData,
+    // Story chapter progress is permanent — survives all resets
+    ...(currentState.story ? { story: currentState.story } : {}),
   };
 
   return { newState, newApotheosisData };