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/wasm-preloader.ts

@@ -1,4 +1,3 @@
-import { getLibreOfficeConverter } from './libreoffice-loader.js';
 import { isWasmAvailable, getWasmBaseUrl } from '../config/wasm-cdn-config.js';
 
 export enum PreloadStatus {
@@ -77,7 +76,7 @@ async function preloadGhostscript(): Promise<void> {
       await import('./ghostscript-loader.js');
 
     const gsModule = await loadGsModule();
-    setCachedGsModule(gsModule as any);
+    setCachedGsModule(gsModule);
     preloadState.ghostscript = PreloadStatus.READY;
     console.log('[Preloader] Ghostscript WASM ready');
   } catch (e) {