Panel redesign, per-server I1 masking, node minimum version 0.5.0, installer output

- UI: settings tab with sections (server, API keys, Prometheus, audit, migrate,
  about); server settings moved there; master keys table rework (menu, chips,
  version, compact phone cards); three-state node version chip
- I1: random per-server template (DNS / QUIC Initial / STUN) kept in users.db,
  GET/POST /api/masking, change from the master keys banner
- Hub rejects nodes older than 0.5.0 (close 4026), /ui/nodes reports outdated
- install.sh: spinner for long commands (full output in the log), step progress
  bar, cards; installs older than 0.5.0 require a full reinstall with data reset
- Bump to Beta 0.5.0

awg-agent/package.json

@@ -1,6 +1,6 @@
 {
   "name": "awg-agent",
-  "version": "0.4.7",
+  "version": "0.5.0",
   "private": true,
   "description": "Агент ноды: держит исходящее WSS-соединение к core и исполняет запросы на локальном awg-ctrl",
   "scripts": {