Add BooksSyncContext, refine database schema, and enhance synchronization support

- Introduce `BooksSyncContext` for managing book synchronization states (server-only, local-only, to-sync, etc.).
- Remove `UserContext` and related dependencies.
- Refine localization strings (`en.json`) with sync-related updates (e.g., "toSyncFromServer", "toSyncToServer").
- Extend database schema with additional tables and fields for syncing books, chapters, and related entities.
- Add `last_update` fields and update corresponding repository methods to support synchronization logic.
- Enhance IPC handlers with stricter typing, data validation, and sync-aware operations.

lib/models/SyncedBook.ts

@@ -0,0 +1,112 @@
+export interface SyncedBook {
+    id: string;
+    type: string;
+    title: string;
+    subTitle: string | null;
+    lastUpdate: number;
+    chapters: SyncedChapter[];
+    characters: SyncedCharacter[];
+    locations: SyncedLocation[];
+    worlds: SyncedWorld[];
+    incidents: SyncedIncident[];
+    plotPoints: SyncedPlotPoint[];
+    issues: SyncedIssue[];
+    actSummaries: SyncedActSummary[];
+    guideLine: SyncedGuideLine | null;
+    aiGuideLine: SyncedAIGuideLine | null;
+}
+
+export interface SyncedChapter {
+    id: string;
+    name: string;
+    lastUpdate: number;
+    contents: SyncedChapterContent[];
+    info: SyncedChapterInfo | null;
+}
+
+export interface SyncedChapterContent {
+    id: string;
+    lastUpdate: number;
+}
+
+export interface SyncedChapterInfo {
+    id: string;
+    lastUpdate: number;
+}
+
+export interface SyncedCharacter {
+    id: string;
+    name: string;
+    lastUpdate: number;
+    attributes: SyncedCharacterAttribute[];
+}
+
+export interface SyncedCharacterAttribute {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedLocation {
+    id: string;
+    name: string;
+    lastUpdate: number;
+    elements: SyncedLocationElement[];
+}
+
+export interface SyncedLocationElement {
+    id: string;
+    name: string;
+    lastUpdate: number;
+    subElements: SyncedLocationSubElement[];
+}
+
+export interface SyncedLocationSubElement {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedWorld {
+    id: string;
+    name: string;
+    lastUpdate: number;
+    elements: SyncedWorldElement[];
+}
+
+export interface SyncedWorldElement {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedIncident {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedPlotPoint {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedIssue {
+    id: string;
+    name: string;
+    lastUpdate: number;
+}
+
+export interface SyncedActSummary {
+    id: string;
+    lastUpdate: number;
+}
+
+export interface SyncedGuideLine {
+    lastUpdate: number;
+}
+
+export interface SyncedAIGuideLine {
+    lastUpdate: number;
+}