Refactor and enhance type safety across various modules

- Updated function parameters and return types in `page-preview.ts`, `pdf-decrypt.ts`, and `pymupdf-loader.ts` for improved type safety.
- Introduced type definitions for `CpdfInstance`, `PyMuPDFInstance`, and other related types to ensure better type checking.
- Enhanced error handling in `sanitize.ts` by creating a utility function for error messages.
- Removed unnecessary type assertions and improved type inference in `editor.ts`, `serialization.ts`, and `tools.test.ts`.
- Added type definitions for markdown-it plugins to improve compatibility and type safety.
- Enforced stricter TypeScript settings by enabling `noImplicitAny` in `tsconfig.json`.
- Cleaned up test files by refining type assertions and ensuring consistency in type usage.

src/js/utils/page-preview.ts

@@ -154,7 +154,7 @@ document.addEventListener('keydown', handleKeydown);
 export function initPagePreview(
   container: HTMLElement,
   pdfjsDoc: PDFDocumentProxy,
-  options: { pageAttr?: string } = {}
+  _options: { pageAttr?: string } = {}
 ): void {
   const totalPages = pdfjsDoc.numPages;