Feature/v2/pageeditor improved (#4289)

# Description of Changes

<!--
Please provide a summary of the changes, including:

Rewrite of page editor to make it work properly.  
Added page breaks
Added merged file support
Added "insert file" support
Slight Ux improvements

Closes #(issue_number)
-->

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: Anthony Stirling <[email protected]>

frontend/src/types/fileContext.ts

@@ -55,6 +55,7 @@ export interface FileRecord {
   blobUrl?: string;
   createdAt?: number;
   processedFile?: ProcessedFileMetadata;
+  insertAfterPageId?: string; // Page ID after which this file should be inserted
   isPinned?: boolean;
   // Note: File object stored in provider ref, not in state
 }
@@ -216,13 +217,14 @@ export type FileContextAction =
 
 export interface FileContextActions {
   // File management - lightweight actions only
-  addFiles: (files: File[]) => Promise<File[]>;
+  addFiles: (files: File[], options?: { insertAfterPageId?: string }) => Promise<File[]>;
   addProcessedFiles: (filesWithThumbnails: Array<{ file: File; thumbnail?: string; pageCount?: number }>) => Promise<File[]>;
   addStoredFiles: (filesWithMetadata: Array<{ file: File; originalId: FileId; metadata: FileMetadata }>) => Promise<File[]>;
   removeFiles: (fileIds: FileId[], deleteFromStorage?: boolean) => Promise<void>;
   updateFileRecord: (id: FileId, updates: Partial<FileRecord>) => void;
   reorderFiles: (orderedFileIds: FileId[]) => void;
   clearAllFiles: () => Promise<void>;
+  clearAllData: () => Promise<void>;
 
   // File pinning
   pinFile: (file: File) => void;

frontend/src/types/pageEditor.ts

@@ -1,10 +1,13 @@
 export interface PDFPage {
   id: string;
   pageNumber: number;
+  originalPageNumber: number;
   thumbnail: string | null;
   rotation: number;
   selected: boolean;
-  splitBefore?: boolean;
+  splitAfter?: boolean;
+  isBlankPage?: boolean;
+  originalFileId?: string;
 }
 
 export interface PDFDocument {
@@ -47,9 +50,17 @@ export interface PageEditorFunctions {
   handleRotate: (direction: 'left' | 'right') => void;
   handleDelete: () => void;
   handleSplit: () => void;
+  handleSplitAll: () => void;
+  handlePageBreak: () => void;
+  handlePageBreakAll: () => void;
+  handleSelectAll: () => void;
+  handleDeselectAll: () => void;
+  handleSetSelectedPages: (pageNumbers: number[]) => void;
   onExportSelected: () => void;
   onExportAll: () => void;
   exportLoading: boolean;
   selectionMode: boolean;
   selectedPages: number[];
+  splitPositions: Set<number>;
+  totalPages: number;
 }