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

src/partials/footer.html

@@ -81,6 +81,11 @@
               >Privacy Policy</a
             >
           </li>
+          <li>
+            <a href="wasm-settings.html" class="hover:text-indigo-400"
+              >Advanced Settings</a
+            >
+          </li>
         </ul>
       </div>