fix(clients): bump auto-generated email length to 10 chars

The "create" form opened with a 9-char random email default, the bulk
modal's random portion was only 6 chars, and the inbound-defaults seed
used 8 — all below the 10-char minimum we want for new clients. Bring
each generator to 10 so an unedited auto-generated email meets the
threshold without the user having to extend it.

frontend/src/lib/xray/inbound-defaults.ts

@@ -46,7 +46,7 @@ interface ClientBase {
 
 function clientBase(seed: ClientBaseSeed = {}): ClientBase {
   return {
-    email: seed.email ?? RandomUtil.randomLowerAndNum(8),
+    email: seed.email ?? RandomUtil.randomLowerAndNum(10),
     limitIp: seed.limitIp ?? 0,
     totalGB: seed.totalGB ?? 0,
     expiryTime: seed.expiryTime ?? 0,

frontend/src/pages/clients/ClientBulkAddModal.tsx

@@ -130,7 +130,7 @@ export default function ClientBulkAddModal({
     const postfix = method > 2 && form.emailPostfix.length > 0 ? form.emailPostfix : '';
     for (let i = start; i < end; i++) {
       let email = '';
-      if (method !== 4) email = RandomUtil.randomLowerAndNum(6);
+      if (method !== 4) email = RandomUtil.randomLowerAndNum(10);
       email += useNum ? prefix + String(i) + postfix : prefix + postfix;
       out.push(email);
     }

frontend/src/pages/clients/ClientFormModal.tsx

@@ -191,7 +191,7 @@ export default function ClientFormModal({
     } else {
       setForm({
         ...emptyForm(),
-        email: RandomUtil.randomLowerAndNum(9),
+        email: RandomUtil.randomLowerAndNum(10),
         uuid: RandomUtil.randomUUID(),
         subId: RandomUtil.randomLowerAndNum(16),
         password: RandomUtil.randomLowerAndNum(16),