feat(amneziawg): add AmneziaWG as an outbound protocol (#6320)

* feat(amneziawg): add AmneziaWG as an outbound protocol

- AmneziaWG outbound protocol end-to-end: config schema, socks bridge, netstack, panel UI
- Route amneziawg outbounds to HTTP probe in TCP mode (backend + frontend classifiers) with pinning test
- Add 2-minute idle read deadline to pumpUDPEgress to reap idle egress sessions
- Require SOCKS5 username/password auth on the egress server (reject NO-AUTH with 0xFF) with test
- Bound the egress TCP tunnel dial with portForwardDialTimeout (10s), matching portfwd.go
- Resolve UDP domain targets off the association's reader loop via deliverUDPDatagram; race-safe getOrDial starts the reply pump at session creation; client passed by value into resolver goroutines (pinned by TestEgressUDPDatagramDomainInterleavedClients)
- Reconcile early-returns on an empty desired set and closes the egress listener; EgressBasePort (64900) is reserved against local inbound port conflicts like the internal API port, with pinning tests for both the port reservation (TestCheckPortConflict_EgressPortBlockedLocal) and the Reconcile empty-desired Close/Listen lifecycle (TestOutboundManagerReconcileEmptyDesiredClosesEgress)
- Eliminate acceptLoop shutdown race by validating listener != nil and registering to tracked under s.mu before wg.Add; bound pre-auth handshake with deadline (pinned by TestEgressServerCloseDuringConcurrentAccepts)
- Support AAAA and dual-stack domain resolution in tunnel DNS resolver with v6 default fallback (DefaultTunnelDNSServerV6); add DNS field to frontend protocol form; avoid unneeded cache flushes on unchanged SetStack ticks

* fix(amneziawg): resolve IPv6-only DNS default fallback and validate required keys

- Default to IPv6 tunnel DNS on IPv6-only outbounds with blank dns
- Require non-empty secretKey and peer publicKey in ValidateAmneziaWGOutbound
- Add end-to-end IPv6 tunnel domain resolution test and test empty key rejection
- Trim comment blocks exceeding 2 lines across modified files
- Fix Storybook test execution on environments with POSIX locale

Co-Authored-By: Claude Code <noreply@anthropic.com>

---------

Co-authored-by: rqzbeh <rqzbeh@users.noreply.github.com>
Co-authored-by: Claude Code <noreply@anthropic.com>
Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

internal/amneziawgnet/resolving_bind.go

@@ -0,0 +1,67 @@
+package amneziawgnet
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/netip"
+	"strconv"
+	"strings"
+	"time"
+
+	awgconn "github.com/amnezia-vpn/amneziawg-go/v3/conn"
+)
+
+// endpointResolveTimeout bounds the one-time DNS lookup in ParseEndpoint.
+const endpointResolveTimeout = 5 * time.Second
+
+// resolvingBind lets peer endpoints be hostnames: StdNetBind has no DNS and
+// an unresolved name kills the whole IpcSet. Resolved once at configure.
+type resolvingBind struct {
+	awgconn.Bind
+}
+
+var lookupEndpointHost = defaultLookupEndpointHost
+
+func defaultLookupEndpointHost(ctx context.Context, host string) ([]netip.Addr, error) {
+	addrs, err := net.DefaultResolver.LookupNetIP(ctx, "ip", host)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]netip.Addr, 0, len(addrs))
+	for _, a := range addrs {
+		out = append(out, a.Unmap())
+	}
+	return out, nil
+}
+
+func newResolvingBind() *resolvingBind {
+	return &resolvingBind{Bind: awgconn.NewDefaultBind()}
+}
+
+// ParseEndpoint resolves hostnames before handing the address to amneziawg-go
+// (whose own implementation accepts literal IPs only).
+func (b *resolvingBind) ParseEndpoint(s string) (awgconn.Endpoint, error) {
+	host, portStr, err := net.SplitHostPort(strings.TrimSpace(s))
+	if err != nil {
+		return nil, fmt.Errorf("endpoint %q: %w", s, err)
+	}
+	port64, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil || port64 == 0 {
+		return nil, fmt.Errorf("endpoint %q: bad port", s)
+	}
+	addr, err := netip.ParseAddr(host)
+	if err != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), endpointResolveTimeout)
+		defer cancel()
+		addrs, rerr := lookupEndpointHost(ctx, host)
+		if rerr != nil {
+			return nil, fmt.Errorf("endpoint %q: resolve host: %w", s, rerr)
+		}
+		if len(addrs) == 0 {
+			return nil, fmt.Errorf("endpoint %q: host resolved to no addresses", s)
+		}
+		addr = addrs[0]
+	}
+	return &awgconn.StdNetEndpoint{AddrPort: netip.AddrPortFrom(addr.Unmap(), uint16(port64))}, nil
+}