fix(clients): use new email after rename and de-duplicate save toast

On client edit the post-update calls (attach/detach/externalLinks) keyed by the original email, so renaming a client made setExternalLinks fail with record-not-found. Key them by the updated email instead.

Each of those sub-step POSTs also auto-toasted its own success, so a save fired the 'Inbound client has been updated' toast twice (or more). Add a silentSuccess HttpUtil option that suppresses the redundant success toast while still surfacing errors and the node-offline warning, and apply it to the attach/detach/externalLinks mutations.

frontend/src/pages/clients/ClientsPage.tsx

@@ -685,16 +685,18 @@ export default function ClientsPage() {
     }
     const updateMsg = await update(meta.email, payload);
     if (!updateMsg?.success) return updateMsg;
+    const rawEmail = (payload as { email?: unknown }).email;
+    const emailKey = typeof rawEmail === 'string' && rawEmail.trim() ? rawEmail.trim() : meta.email;
     if (Array.isArray(meta.attach) && meta.attach.length > 0) {
-      const r = await attach(meta.email, meta.attach);
+      const r = await attach(emailKey, meta.attach);
       if (!r?.success) return r;
     }
     if (Array.isArray(meta.detach) && meta.detach.length > 0) {
-      const r = await detach(meta.email, meta.detach);
+      const r = await detach(emailKey, meta.detach);
       if (!r?.success) return r;
     }
     // Always replace the client's external links (an empty set clears them).
-    const r = await setExternalLinks(meta.email, meta.externalLinks);
+    const r = await setExternalLinks(emailKey, meta.externalLinks);
     if (!r?.success) return r;
     return updateMsg;
   }, [create, update, attach, detach, setExternalLinks]);