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

index.html

@@ -209,6 +209,21 @@
               </svg>
             </span>
           </a>
+          <!-- DigitalOcean -->
+          <a
+            href="https://www.digitalocean.com/?refcode=d93c189ef6d0&utm_campaign=Referral_Invite&utm_medium=Referral_Program&utm_source=badge"
+            target="_blank"
+            rel="noopener noreferrer"
+            class="mt-8 opacity-50 hover:opacity-100 transition-opacity duration-300 hide-section"
+          >
+            <img
+              src="/images/badge.svg"
+              alt="DigitalOcean Referral Badge"
+              width="150"
+              height="32"
+              class="h-8"
+            />
+          </a>
         </div>
       </section>
 
@@ -701,6 +716,28 @@
                   ></div>
                 </label>
               </div>
+
+              <!-- Advanced Settings Link -->
+              <a
+                href="wasm-settings.html"
+                class="flex items-center justify-between p-4 bg-gray-900 rounded-lg border border-gray-700 hover:bg-gray-800 hover:border-indigo-500/50 transition-all group"
+              >
+                <div class="flex-1">
+                  <span
+                    class="text-sm font-medium text-gray-200 group-hover:text-white"
+                  >
+                    Advanced Settings
+                  </span>
+                  <p class="text-xs text-gray-400 mt-1">
+                    Configure external processing modules (PyMuPDF, Ghostscript,
+                    CoherentPDF)
+                  </p>
+                </div>
+                <i
+                  data-lucide="chevron-right"
+                  class="w-5 h-5 text-gray-500 group-hover:text-indigo-400 transition-colors"
+                ></i>
+              </a>
             </div>
           </div>