Fix bugs and add features to Znakopis document management

- Fix API endpoint for creating pages (documents/:id/pages)
- Fix sentence deletion functionality
- Add CreateDocumentDialog component for better UX
- Improve document and sentence management UI
- Update seed data and backend routes
- Clean up documentation files (remove videos.md, videosentence.md)
- Add comprehensive bug tracking in fixbugsaddfeatures.md

packages/frontend/src/lib/documentApi.ts

@@ -85,7 +85,7 @@ export const documentApi = {
 
   // Create a new page in a document
   async createPage(documentId: string, title?: string): Promise<DocumentPage> {
-    const response = await api.post(`/api/${documentId}/pages`, { title });
+    const response = await api.post(`/api/documents/${documentId}/pages`, { title });
     return response.data.page;
   },
 
@@ -96,7 +96,7 @@ export const documentApi = {
     data: CreateSentenceData
   ): Promise<Sentence> {
     const response = await api.post(
-      `/api/${documentId}/pages/${pageIndex}/sentences`,
+      `/api/documents/${documentId}/pages/${pageIndex}/sentences`,
       data
     );
     return response.data.sentence;