fix(copy): drop the 'no telemetry' over-claim on the no-signup page

Cloudflare RUM (cookieless, no cross-site) stays on as the signal that
distinguishes real human traffic from bots, so a blanket 'no telemetry' claim
is no longer accurate. Reword to the still-true point: the code is open, so you
can confirm your files are never uploaded. (This change was in PR #106 but got
separated when #106 was squash-merged without it.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: chaxus

public/no-signup-document-editor.html

@@ -140,8 +140,9 @@ <h2>Why people use it</h2>
       </ul>
 
       <div class="oss">
-        <strong>Open source &amp; self-hostable.</strong> This editor is fully open source under the AGPL-3.0 license —
-        there is no hidden telemetry and nothing to trust us on. Read the code, file issues, or run your own copy:
+        <strong>Open source &amp; self-hostable.</strong> This editor is fully open source under the AGPL-3.0 license,
+        so you don't have to take our word for it — read the code to confirm your files are never uploaded, file issues,
+        or run your own copy:
         <a href="https://github.com/ranuts/document" rel="noopener">github.com/ranuts/document</a>.
       </div>