feat: integrate customer service chat

web/src/mobile/im.ts

@@ -76,9 +76,10 @@ export class CustomerServiceChat {
     const ref = await this.upload(file, onProgress);
     const descriptor = {
       mime: file.type,
-      // Tinode returns a relative file path. Publish an absolute reference so
-      // other clients do not resolve it against their own web-app origin.
-      refurl: new URL(ref, this.session.api_base_url).toString(),
+      // Keep the server-issued relative reference. Tinode only includes
+      // relative references in extra.attachments, which lets the server bind
+      // the uploaded file to this message and authorize the recipient.
+      refurl: ref,
       filename: file.name,
       size: file.size,
       width: dimensions.width,
@@ -187,8 +188,8 @@ export class CustomerServiceChat {
     if (!ref) return '';
     const apiBase = new URL(this.session.api_base_url);
     const resolved = new URL(ref, apiBase);
-    // The SDK only signs relative file URLs. Convert our absolute IM file
-    // reference back to a relative path for signing when rendering locally.
+    // The SDK signs relative file URLs. Also tolerate historical absolute IM
+    // references by converting same-origin URLs back to a signable path.
     const signable = resolved.origin === apiBase.origin
       ? `${resolved.pathname}${resolved.search}`
       : ref;