Add sen:// subscription with master keys

A master key is a sen:// link with a device limit. Each device
generates its own WireGuard keypair and registers only the public key,
then polls a signed /sub/v1/config, so params and generation changes
reach users without re-importing a key.

- awg-ctrl: peers table and /api/peers*, /api/profile; nextIp and
  rebuildConf take peers into account (output unchanged without them)
- awg-ui: link codec and signatures (sen.ts), registry, panel routes
  and the public listener on SUB_PORT (sub.ts)
- responses are always Ed25519-signed; TLS with a pinned self-signed
  certificate is optional
- devices report a client version, shown as platform-version
- "Мастер-ключи" tab: a table with the devices nested under each key,
  a device-limit meter, per-key settings and a placeholder for the
  servers a key serves; cards on mobile
- install.sh/CLI: subscription signing key, optional certificate, port;
  kept across reinstalls with KEEP_DATA
- add the missing mock-server.ts used by npm run dev:mock

cli/src/index.ts

@@ -93,6 +93,13 @@ const SERVICES = {
             // ui.db (ключи внешнего API) в каталоге данных AWG (вне PROJECT) —
             // переживает переустановку.
             UI_DB_FILE:   process.env.UI_DB_FILE      ?? "/etc/amnezia/amneziawg/ui.db",
+            // Подписка sen:// (мастер-ключи SenAWG): порт, режим TLS, ключ подписи и
+            // сертификат. Без SUB_PORT или ключа подписи awg-ui подписку не поднимает.
+            SUB_PORT:          process.env.SUB_PORT          ?? "",
+            SUB_TLS:           process.env.SUB_TLS           ?? "off",
+            SUB_SIGN_KEY_FILE: process.env.SUB_SIGN_KEY_FILE ?? "/etc/amnezia/amneziawg/sub_sign.key",
+            SUB_TLS_KEY_FILE:  process.env.SUB_TLS_KEY_FILE  ?? "/etc/amnezia/amneziawg/sub_tls.key",
+            SUB_TLS_CERT_FILE: process.env.SUB_TLS_CERT_FILE ?? "/etc/amnezia/amneziawg/sub_tls.crt",
         },
         pidFile: "/tmp/awg-ui.pid",
         logFile: path.join(LOGS, "awg-ui.log"),