Add QuillSense support with settings and integration

- Introduced new "QuillSense" feature for AI-assisted book creation.
- Added QuillSense settings panel with advanced options and disable/enable functionality.
- Updated GhostWriter and TextEditor components to respect QuillSense settings.
- Extended models and repositories to track and manage QuillSense state per book.
- Localized new strings for English and French.

components/ghostwriter/GhostWriter.tsx

@@ -260,19 +260,25 @@ export default function GhostWriter() {
         }
     }
     
-    if (!hasAccess) {
+    if (!hasAccess || !book?.quillsenseEnabled) {
         return (
             <div className="flex items-center justify-center h-full">
                 <div
                     className="bg-tertiary/90 backdrop-blur-sm p-10 rounded-2xl shadow-2xl text-center border border-secondary/50 max-w-md">
                     <h2 className="text-2xl font-['ADLaM_Display'] text-text-primary mb-4">{t("ghostWriter.title")}</h2>
-                    <p className="text-muted mb-6 text-lg leading-relaxed">{t("ghostWriter.subscriptionRequired")}</p>
-                    <button
-                        onClick={(): string => window.location.href = '/pricing'}
-                        className="px-6 py-3 bg-primary text-text-primary rounded-xl hover:bg-primary-dark transition-all duration-200 hover:scale-105 shadow-md hover:shadow-lg font-semibold"
-                    >
-                        {t("ghostWriter.subscribe")}
-                    </button>
+                    <p className="text-muted mb-6 text-lg leading-relaxed">
+                        {!book?.quillsenseEnabled
+                            ? t("ghostWriter.quillsenseDisabled")
+                            : t("ghostWriter.subscriptionRequired")}
+                    </p>
+                    {hasAccess && !book?.quillsenseEnabled ? null : (
+                        <button
+                            onClick={(): string => window.location.href = '/pricing'}
+                            className="px-6 py-3 bg-primary text-text-primary rounded-xl hover:bg-primary-dark transition-all duration-200 hover:scale-105 shadow-md hover:shadow-lg font-semibold"
+                        >
+                            {t("ghostWriter.subscribe")}
+                        </button>
+                    )}
                 </div>
             </div>
         );