Remove Story model handling verbal styles and linguistic properties

- Delete `Story` model implementation including `getVerbesStyle` method and related properties.
- Cleanup unused interfaces and redundant logic from the codebase.

lib/models/Book.ts

@@ -46,13 +46,14 @@ export interface GuideLine {
 }
 
 export interface GuideLineAI {
-    narrativeType: number;
-    dialogueType: number;
-    globalResume: string;
-    atmosphere: string;
-    verbeTense: number;
-    langue: number;
-    themes: string;
+    narrativeType: number|null;
+    dialogueType: number|null;
+    globalResume: string|null;
+    atmosphere: string|null;
+    verbeTense: number|null;
+    langue: number|null;
+    currentResume: string|null;
+    themes: string|null;
 }
 
 export interface PlotPoint {