diff --git a/admin.html b/admin.html
index 5e6cd1f..a0cbf9d 100644
--- a/admin.html
+++ b/admin.html
@@ -873,11 +873,6 @@ function statusBadge(active, daysLeft) {
   if (daysLeft <= 2) return '<span class="badge warn">' + daysLeft + ' дн.</span>';
   return '<span class="badge ok">' + daysLeft + ' дн.</span>';
 }
-function staggerReveal(container) {
-  const items = container.querySelectorAll(".reveal");
-  items.forEach((el, i) => { el.style.animationDelay = (i * 0.04) + "s"; });
-}
-
 async function loadDashboard() {
   const stats = await api("/admin/api/stats");
   const grid = document.getElementById("stat-grid");
@@ -888,9 +883,8 @@ async function loadDashboard() {
     ["Гифт-коды (созд./исп.)", stats.gifts_created + " / " + stats.gifts_used, "var(--pink)", ICONS.gift],
   ].map(([l, v, c, ic], i) => statCard(l, v, c, ic, i * 0.05)).join("");
 
-  const subs = await api("/admin/api/subscriptions");
+  const recent = await api("/admin/api/subscriptions?limit=8");
   const body = document.getElementById("recent-subs-body");
-  const recent = subs.slice(0, 8);
   body.innerHTML = recent.length ? recent.map((s, i) => `
     <tr ${rowAttr(i)}><td>${s.username ? "@" + esc(s.username) : "tg" + s.tg_id}</td><td>${esc(s.node_label)}</td><td>${esc(s.plan_label)}</td>
     <td>${fmtDate(s.expires_at)}</td><td>${statusBadge(s.active, s.days_left)}</td></tr>
diff --git a/api.py b/api.py
index f73b654..9f5cac3 100644
--- a/api.py
+++ b/api.py
@@ -1,3 +1,4 @@
+import asyncio
 import datetime
 import json
 import os
@@ -241,16 +242,15 @@ def get_subscription(token: str, request: Request):
         hwid = request.headers.get("x-hwid", "")
         if not HWID_RE.match(hwid):
             raise HTTPException(404, "hwid required")
-        if not db.get_device(user["tg_id"], hwid):
-            limit = user["hwid_limit"] or HWID_FALLBACK_LIMIT
-            if db.count_devices(user["tg_id"]) >= limit:
-                raise HTTPException(404, "device limit reached", headers={"x-hwid-max-devices-reached": "true"})
-            db.add_device(
-                user["tg_id"], hwid,
-                request.headers.get("x-device-os"),
-                request.headers.get("x-device-model"),
-                ua,
-            )
+        limit = user["hwid_limit"] if user["hwid_limit"] is not None else HWID_FALLBACK_LIMIT
+        _, allowed = db.add_device_if_under_limit(
+            user["tg_id"], hwid, limit,
+            request.headers.get("x-device-os"),
+            request.headers.get("x-device-model"),
+            ua,
+        )
+        if not allowed:
+            raise HTTPException(404, "device limit reached", headers={"x-hwid-max-devices-reached": "true"})
 
     content = links.build_subscription_text(subs)
     return Response(content=content, media_type="text/plain")
@@ -305,13 +305,16 @@ def _tg_send_message(tg_id: int, text: str):
 
 
 def _grant_paid_subscription(payment_id: str):
-    payment = db.mark_payment_paid(payment_id)
-    if not payment:
+    payment = db.get_payment(payment_id)
+    if not payment or payment["status"] == "paid":
         return
     plan = PLANS_BY_CODE.get(payment["plan"])
     node = db.get_node(payment["node"])
     if not plan or not node:
         return
+    payment = db.mark_payment_paid(payment_id)
+    if not payment:
+        return
     sub = db.create_subscription(payment["tg_id"], payment["node"], plan["days"], payment["plan"], source="payment")
     xray_manager.add_client_to_node(node, sub["uuid"], email=sub["uuid"])
     user = db.get_or_create_user(payment["tg_id"], None)
@@ -343,9 +346,10 @@ def _check_and_reconcile_payment(payment: dict) -> str:
 @app.get("/admin/api/payments")
 def admin_list_payments(request: Request):
     require_admin(request)
+    nodes_by_code = {n["code"]: n for n in db.list_nodes()}
     out = []
     for p in db.list_payments():
-        node = db.get_node(p["node"])
+        node = nodes_by_code.get(p["node"])
         plan = PLANS_BY_CODE.get(p["plan"])
         out.append({
             **p,
@@ -374,12 +378,16 @@ async def yookassa_webhook(request: Request):
     if not payments.verify_yookassa_notification(body):
         raise HTTPException(400, "unexpected event")
     obj = body.get("object", {})
-    if obj.get("status") != "succeeded":
-        return {"ok": True}
     payment_id = (obj.get("metadata") or {}).get("payment_id")
     if not payment_id:
         raise HTTPException(400, "missing payment_id")
-    _grant_paid_subscription(payment_id)
+    payment = db.get_payment(payment_id)
+    if not payment or not payment.get("external_id"):
+        raise HTTPException(400, "unknown payment")
+    status = await asyncio.to_thread(payments.check_yookassa_payment, payment["external_id"])
+    if status not in payments.PAID_STATUSES:
+        return {"ok": True}
+    await asyncio.to_thread(_grant_paid_subscription, payment_id)
     return {"ok": True}
 
 
@@ -394,7 +402,7 @@ async def platega_webhook(request: Request):
     payment_id = body.get("id") or body.get("paymentId")
     if status not in ("succeeded", "success", "paid") or not payment_id:
         return {"ok": True}
-    _grant_paid_subscription(payment_id)
+    await asyncio.to_thread(_grant_paid_subscription, payment_id)
     return {"ok": True}
 
 
@@ -519,12 +527,13 @@ def admin_traffic(request: Request):
     total_down = sum(v["down"] for v in all_stats.values())
 
     subs = db.list_all_subscriptions(limit=5000)
+    nodes_by_code = {n["code"]: n for n in db.list_nodes()}
     per_sub = []
     for s in subs:
         st = all_stats.get(s["uuid"])
         if not st:
             continue
-        node = db.get_node(s["node"])
+        node = nodes_by_code.get(s["node"])
         per_sub.append({
             "uuid": s["uuid"],
             "username": ("@" + s["username"]) if s.get("username") else f"tg{s['tg_id']}",
@@ -544,12 +553,13 @@ def admin_traffic(request: Request):
 
 
 @app.get("/admin/api/subscriptions")
-def admin_subscriptions(request: Request):
+def admin_subscriptions(request: Request, limit: int = 200):
     require_admin(request)
-    subs = db.list_all_subscriptions()
+    subs = db.list_all_subscriptions(limit=limit)
+    nodes_by_code = {n["code"]: n for n in db.list_nodes()}
     out = []
     for s in subs:
-        node = db.get_node(s["node"])
+        node = nodes_by_code.get(s["node"])
         plan = PLANS_BY_CODE.get(s["plan"])
         out.append({
             **s,
@@ -563,8 +573,7 @@ def admin_subscriptions(request: Request):
 @app.post("/admin/api/subscriptions/{uuid}/revoke")
 def admin_revoke_subscription(uuid: str, request: Request):
     require_admin(request)
-    subs = db.list_all_subscriptions(limit=5000)
-    sub = next((s for s in subs if s["uuid"] == uuid), None)
+    sub = db.get_subscription(uuid)
     if not sub:
         raise HTTPException(404, "not found")
     node = db.get_node(sub["node"])
@@ -577,8 +586,7 @@ def admin_revoke_subscription(uuid: str, request: Request):
 @app.post("/admin/api/subscriptions/{uuid}/reset-traffic")
 def admin_reset_traffic(uuid: str, request: Request):
     require_admin(request)
-    subs = db.list_all_subscriptions(limit=5000)
-    sub = next((s for s in subs if s["uuid"] == uuid), None)
+    sub = db.get_subscription(uuid)
     if not sub:
         raise HTTPException(404, "not found")
     node = db.get_node(sub["node"])
@@ -595,9 +603,10 @@ def admin_user_card(tg_id: int, request: Request):
     if not user:
         raise HTTPException(404, "not found")
     subs = db.list_subscriptions_for_user(tg_id)
+    nodes_by_code = {n["code"]: n for n in db.list_nodes()}
     out_subs = []
     for s in subs:
-        node = db.get_node(s["node"])
+        node = nodes_by_code.get(s["node"])
         plan = PLANS_BY_CODE.get(s["plan"])
         out_subs.append({
             **s,
@@ -662,9 +671,10 @@ def admin_set_hwid_limit(tg_id: int, request: Request, body: dict = Body(...)):
 def admin_gift_codes(request: Request):
     require_admin(request)
     codes = db.list_gift_codes()
+    nodes_by_code = {n["code"]: n for n in db.list_nodes()}
     out = []
     for c in codes:
-        node = db.get_node(c["node"])
+        node = nodes_by_code.get(c["node"])
         plan = PLANS_BY_CODE.get(c["plan"])
         out.append({
             **c,
diff --git a/bot.py b/bot.py
index 3d674ec..3e95e6e 100644
--- a/bot.py
+++ b/bot.py
@@ -96,10 +96,13 @@ async def start_deeplink(message: Message, command: CommandObject):
         if err == "already_used":
             await message.answer("Этот код уже был использован.")
             return await send_main_menu(message)
-        plan = PLANS_BY_CODE[gift["plan"]]
-        sub = db.create_subscription(message.from_user.id, gift["node"], plan["days"], plan["code"], source="gift", )
+        plan = PLANS_BY_CODE.get(gift["plan"])
         gift_node = db.get_node(gift["node"])
-        xray_manager.add_client_to_node(gift_node, sub["uuid"], email=sub["uuid"])
+        if not plan or not gift_node:
+            await message.answer("Этот подарок больше недоступен.")
+            return await send_main_menu(message)
+        sub = db.create_subscription(message.from_user.id, gift["node"], plan["days"], plan["code"], source="gift", )
+        await asyncio.to_thread(xray_manager.add_client_to_node, gift_node, sub["uuid"], email=sub["uuid"])
         await message.answer(
             f"<b>Подарок активирован</b>\n\n"
             f"Сервер: {gift_node['label']}\n"
@@ -171,7 +174,7 @@ async def cb_plan(cb: CallbackQuery):
     user = db.get_or_create_user(cb.from_user.id, cb.from_user.username)
     sub = db.create_subscription(cb.from_user.id, node_code, plan["days"], plan_code, source="bot")
     node_row = db.get_node(node_code)
-    xray_manager.add_client_to_node(node_row, sub["uuid"], email=sub["uuid"])
+    await asyncio.to_thread(xray_manager.add_client_to_node, node_row, sub["uuid"], email=sub["uuid"])
     kb = connect_kb(user["token"], extra_rows=[
         [InlineKeyboardButton(text="Моя подписка", callback_data="menu:mysub")],
         [InlineKeyboardButton(text="В меню", callback_data="menu:main")],
@@ -309,7 +312,7 @@ async def cb_admin_stats(cb: CallbackQuery):
 async def cb_admin_sync(cb: CallbackQuery):
     if not is_admin(cb.from_user.id):
         return await cb.answer("Нет доступа", show_alert=True)
-    result = xray_manager.sync_all()
+    result = await asyncio.to_thread(xray_manager.sync_all)
     kb = InlineKeyboardMarkup(inline_keyboard=[[InlineKeyboardButton(text="В админку", callback_data="menu:admin")]])
     await cb.message.edit_text(
         f"Синхронизация xray выполнена.\nАктивно клиентов: {result['active_now']}\n"
@@ -326,19 +329,19 @@ async def reconcile_pending_payments():
         if payment["status"] != "pending" or not payment.get("external_id"):
             continue
         try:
-            status = payments.check_payment_status(payment["provider"], payment["external_id"])
+            status = await asyncio.to_thread(payments.check_payment_status, payment["provider"], payment["external_id"])
         except Exception:
             continue
         if status in payments.PAID_STATUSES:
-            granted = db.mark_payment_paid(payment["id"])
-            if not granted:
-                continue
             plan = PLANS_BY_CODE.get(payment["plan"])
             node_row = db.get_node(payment["node"])
             if not plan or not node_row:
                 continue
+            granted = db.mark_payment_paid(payment["id"])
+            if not granted:
+                continue
             sub = db.create_subscription(payment["tg_id"], payment["node"], plan["days"], payment["plan"], source="payment")
-            xray_manager.add_client_to_node(node_row, sub["uuid"], email=sub["uuid"])
+            await asyncio.to_thread(xray_manager.add_client_to_node, node_row, sub["uuid"], email=sub["uuid"])
             user = db.get_or_create_user(payment["tg_id"], None)
             try:
                 await bot.send_message(
@@ -357,7 +360,7 @@ async def reconcile_pending_payments():
 async def periodic_sync():
     while True:
         try:
-            xray_manager.sync_all()
+            await asyncio.to_thread(xray_manager.sync_all)
         except Exception:
             log.exception("periodic sync failed")
         try:
diff --git a/db.py b/db.py
index b16ecfd..fd59685 100644
--- a/db.py
+++ b/db.py
@@ -1,3 +1,4 @@
+import os
 import sqlite3
 import secrets
 import datetime
@@ -145,6 +146,13 @@ def init_db():
         conn.executescript(SCHEMA)
     _migrate()
     _seed_local_node()
+    for suffix in ("", "-wal", "-shm"):
+        path = DB_PATH + suffix
+        if os.path.exists(path):
+            try:
+                os.chmod(path, 0o600)
+            except OSError:
+                pass
 
 
 def _seed_local_node():
@@ -231,6 +239,12 @@ def delete_node(code: str):
     if code == "de1":
         raise ValueError("cannot delete the local node")
     with get_conn() as conn:
+        active = conn.execute(
+            "SELECT COUNT(*) c FROM subscriptions WHERE node=? AND active=1 AND expires_at>?",
+            (code, now_iso()),
+        ).fetchone()["c"]
+        if active:
+            raise ValueError(f"node has {active} active subscriptions, revoke them first")
         conn.execute("DELETE FROM nodes WHERE code=?", (code,))
 
 
@@ -360,6 +374,16 @@ def revoke_subscription(client_uuid: str):
         conn.execute("UPDATE subscriptions SET active=0 WHERE uuid=?", (client_uuid,))
 
 
+def get_subscription(client_uuid: str):
+    with get_conn() as conn:
+        row = conn.execute(
+            "SELECT s.*, u.username FROM subscriptions s "
+            "LEFT JOIN users u ON u.tg_id = s.tg_id WHERE s.uuid=?",
+            (client_uuid,),
+        ).fetchone()
+        return dict(row) if row else None
+
+
 def get_user(tg_id: int):
     with get_conn() as conn:
         row = conn.execute("SELECT * FROM users WHERE tg_id=?", (tg_id,)).fetchone()
@@ -427,13 +451,12 @@ def set_payment_external(payment_id: str, external_id: str, pay_url: str):
 
 def mark_payment_paid(payment_id: str):
     with get_conn() as conn:
-        row = conn.execute("SELECT status FROM payments WHERE id=?", (payment_id,)).fetchone()
-        if not row or row["status"] == "paid":
-            return None
-        conn.execute(
-            "UPDATE payments SET status='paid', paid_at=? WHERE id=?",
+        cur = conn.execute(
+            "UPDATE payments SET status='paid', paid_at=? WHERE id=? AND status='pending'",
             (now_iso(), payment_id),
         )
+        if cur.rowcount == 0:
+            return None
     return get_payment(payment_id)
 
 
@@ -483,6 +506,23 @@ def add_device(tg_id: int, hwid: str, device_os: str | None, device_model: str |
     return get_device(tg_id, hwid)
 
 
+def add_device_if_under_limit(tg_id: int, hwid: str, limit: int, device_os: str | None, device_model: str | None, user_agent: str | None):
+    with get_conn() as conn:
+        conn.execute("BEGIN IMMEDIATE")
+        existing = conn.execute("SELECT * FROM devices WHERE tg_id=? AND hwid=?", (tg_id, hwid)).fetchone()
+        if existing:
+            return dict(existing), True
+        count = conn.execute("SELECT COUNT(*) c FROM devices WHERE tg_id=?", (tg_id,)).fetchone()["c"]
+        if count >= limit:
+            return None, False
+        conn.execute(
+            "INSERT INTO devices (tg_id, hwid, device_os, device_model, user_agent, first_seen) VALUES (?,?,?,?,?,?)",
+            (tg_id, hwid, device_os, device_model, user_agent, now_iso()),
+        )
+        row = conn.execute("SELECT * FROM devices WHERE tg_id=? AND hwid=?", (tg_id, hwid)).fetchone()
+        return dict(row), True
+
+
 def delete_device(device_id: int):
     with get_conn() as conn:
         conn.execute("DELETE FROM devices WHERE id=?", (device_id,))
diff --git a/nodeprov.py b/nodeprov.py
index 32f547b..9b4fb31 100644
--- a/nodeprov.py
+++ b/nodeprov.py
@@ -8,6 +8,7 @@ import paramiko
 from config import PANEL_DOMAIN
 
 MGMT_KEY_PATH = "/root/.ssh/mbs_nodes_ed25519"
+MGMT_KNOWN_HOSTS_PATH = "/root/.ssh/mbs_nodes_known_hosts"
 LOCAL_TAGS = {"vless-tcp-reality", "vless-grpc-reality", "vless-xhttp-reality", "vless-ws-tls"}
 TAG_FLOW = {"vless-tcp-reality": "xtls-rprx-vision"}
 
@@ -238,9 +239,14 @@ def render_install_script(node: dict) -> str:
 
 def _mgmt_connect(address: str, ssh_port: int = 22) -> paramiko.SSHClient:
     client = paramiko.SSHClient()
+    try:
+        client.load_host_keys(MGMT_KNOWN_HOSTS_PATH)
+    except IOError:
+        pass
     client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
     key = paramiko.Ed25519Key.from_private_key_file(MGMT_KEY_PATH)
     client.connect(address, port=ssh_port, username="root", pkey=key, timeout=15, banner_timeout=15, auth_timeout=15)
+    client.save_host_keys(MGMT_KNOWN_HOSTS_PATH)
     return client
 
 
diff --git a/xray_manager.py b/xray_manager.py
index 0c75c20..4c1d04e 100644
--- a/xray_manager.py
+++ b/xray_manager.py
@@ -75,15 +75,6 @@ def remove_client(client_uuid: str):
             _reload_xray()
 
 
-def list_client_ids():
-    with _locked():
-        cfg = _load()
-        ids = set()
-        for ib in _local_inbounds(cfg):
-            ids |= {c["id"] for c in ib["settings"]["clients"]}
-        return ids
-
-
 def sync_from_db():
     import db as dbmod