feat(6867): Settings → Config has a Reverse proxy section that shows which count is right

The section opens with a verdict on the admin's own request: the
address Grimoire reads them as, or, through Cloudflare, the count to set
with a button that sets it. Below it are the count with where it came
from, a table of what counts 0-3 would read, and the raw forwarding
chain. A saved count can be cleared back to the environment's.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/views/SettingsView.vue

@@ -9,6 +9,7 @@ import { apiGet, apiPost, apiPut, apiDelete, listGroups, createGroup, deleteGrou
 import type { User } from "@/types/auth";
 import PaginationBar from "@/components/PaginationBar.vue";
 import MomentsSettings from "@/components/MomentsSettings.vue";
+import ReverseProxySettings from "@/components/ReverseProxySettings.vue";
 import ReplyShapesSettings from "@/components/ReplyShapesSettings.vue";
 import BackupScheduleSettings from "@/components/BackupScheduleSettings.vue";
 import RestoreBackupDialog from "@/components/RestoreBackupDialog.vue";
@@ -2664,6 +2665,16 @@ async function deleteUser(userId: number) {
         <div v-else class="empty-msg">Nothing asked yet.</div>
       </section>
 
+      <section class="settings-section full-width">
+        <h2>Reverse proxy</h2>
+        <p class="section-desc">
+          How many proxies a request passes through before it reaches Grimoire. Sign-in rate
+          limits and the audit log key on the visitor's address, read through this count; if it
+          is too low, every visitor reads as the proxy and one run of bad sign-ins blocks everyone.
+        </p>
+        <ReverseProxySettings />
+      </section>
+
       <section class="settings-section full-width">
         <h2>Application URL</h2>
         <p class="section-desc">