feat: separate AGPL libraries and add dynamic WASM loading

- Add WASM settings page for configuring external AGPL modules
- Implement dynamic loading for PyMuPDF, Ghostscript, and CoherentPDF
- Add Cloudflare Worker proxy for serving WASM files with CORS
- Update all affected tool pages to check WASM availability
- Add showWasmRequiredDialog for missing module configuration

Documentation:
- Update README, licensing.html, and docs to clarify AGPL components
  are not bundled and must be configured separately
- Add WASM-PROXY.md deployment guide with recommended source URLs
- Rename "CPDF" to "CoherentPDF" for consistency

public/workers/alternate-merge.worker.d.ts

@@ -1,23 +1,24 @@
 declare const coherentpdf: typeof import('../../src/types/coherentpdf.global').coherentpdf;
 
 interface InterleaveFile {
-    name: string;
-    data: ArrayBuffer;
+  name: string;
+  data: ArrayBuffer;
 }
 
 interface InterleaveMessage {
-    command: 'interleave';
-    files: InterleaveFile[];
+  command: 'interleave';
+  files: InterleaveFile[];
+  cpdfUrl?: string;
 }
 
 interface InterleaveSuccessResponse {
-    status: 'success';
-    pdfBytes: ArrayBuffer;
+  status: 'success';
+  pdfBytes: ArrayBuffer;
 }
 
 interface InterleaveErrorResponse {
-    status: 'error';
-    message: string;
+  status: 'error';
+  message: string;
 }
 
 type InterleaveResponse = InterleaveSuccessResponse | InterleaveErrorResponse;