feat: web-vnc single-binary browser VNC gateway with password access

- Go stdlib-only gateway: serves noVNC client, password auth, WS<->TCP relay
- auth: PBKDF2-HMAC-SHA256 password hash, HMAC session cookies, login rate limit
- relay: hand-written RFC 6455 WebSocket + transparent RFB bridge
- vncspawner: cross-OS VNC server detection/launch (Windows/Linux/macOS)
- server: /login /logout /vnc /api/status routes, session middleware, embed.FS
- scripts: get-novnc, get-vnc (zip-verified), list-ips, open-firewall
- run.bat: one-click launcher (asks only password), lists access IPs
- README/AGENTS.md (Russian), .gitignore (root-anchored binaries)

scripts/list-ips.ps1

@@ -0,0 +1,33 @@
+# list-ips.ps1 — prints reachable IPv4 addresses of this machine (one per line).
+# Used by run.bat to show http://<ip>:8080 access URLs.
+$ErrorActionPreference = "SilentlyContinue"
+$ips = New-Object System.Collections.Generic.List[string]
+
+# Primary: pure .NET network interfaces (locale independent).
+try {
+  [System.Net.NetworkInformation.NetworkInterface]::GetAllNetworkInterfaces() |
+    Where-Object {
+      $_.OperationalStatus -eq [System.Net.NetworkInformation.OperationalStatus]::Up -and
+      $_.NetworkInterfaceType -ne [System.Net.NetworkInformation.NetworkInterfaceType]::Loopback
+    } |
+    ForEach-Object { $_.GetIPProperties().UnicastAddresses } |
+    Where-Object {
+      $_.Address.AddressFamily -eq [System.Net.Sockets.AddressFamily]::InterNetwork -and
+      $_.Address.IPAddressToString -notlike "127.*" -and
+      $_.Address.IPAddressToString -notlike "169.254.*"
+    } |
+    ForEach-Object { $ips.Add($_.Address.IPAddressToString) }
+} catch {}
+
+# Fallback: parse ipconfig (handles localized output via the "IPv4" token).
+if ($ips.Count -eq 0) {
+  ipconfig | Select-String -Pattern "IPv4" | ForEach-Object {
+    if ($_ -match "(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})") {
+      $ip = $matches[1]
+      if ($ip -notlike "127.*" -and $ip -notlike "169.254.*") { $ips.Add($ip) }
+    }
+  }
+}
+
+# Deduplicate and print.
+$ips | Sort-Object -Unique | ForEach-Object { Write-Output $_ }