Release 3.8.1.1: lighter idle UI poll, core cache, multicore ping.

Reduce idle CPU (cheap PollUI, binary cache, logbuf cap, DOM fingerprint),
speed ping/AWG HostPort, CopyBuffer pool; ship arm64 build and update notes.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/protocols/awg/conf.go

@@ -454,7 +454,11 @@ func (c *Conf) validate() error {
 }
 
 // HostPort returns UDP endpoint host and port for ping.
+// Prefers a light Endpoint=/URI extract; falls back to full Parse for JSON/vpn:// blobs.
 func HostPort(raw string) (host, port string, err error) {
+	if h, p, ok := lightEndpoint(raw); ok {
+		return h, p, nil
+	}
 	c, err := Parse(raw)
 	if err != nil {
 		return "", "", err
@@ -466,6 +470,67 @@ func HostPort(raw string) (host, port string, err error) {
 	return h, p, nil
 }
 
+func lightEndpoint(raw string) (host, port string, ok bool) {
+	raw = sanitizeShare(raw)
+	if raw == "" {
+		return "", "", false
+	}
+	lower := strings.ToLower(raw)
+	switch {
+	case strings.HasPrefix(lower, "awg://"), strings.HasPrefix(lower, "amneziawg://"),
+		strings.HasPrefix(lower, "wireguard://"):
+		// URI host:port only — no full config decode.
+		rest := raw
+		if i := strings.Index(rest, "://"); i >= 0 {
+			rest = rest[i+3:]
+		}
+		if at := strings.Index(rest, "@"); at >= 0 {
+			rest = rest[at+1:]
+		}
+		if i := strings.IndexAny(rest, "/?#"); i >= 0 {
+			rest = rest[:i]
+		}
+		rest = strings.TrimSpace(rest)
+		if rest == "" {
+			return "", "", false
+		}
+		h, p, err := net.SplitHostPort(rest)
+		if err != nil {
+			return rest, "51820", true
+		}
+		return h, p, true
+	}
+	if strings.Contains(lower, "endpoint") {
+		for _, line := range strings.Split(raw, "\n") {
+			line = strings.TrimSpace(line)
+			if line == "" || strings.HasPrefix(line, "#") || strings.HasPrefix(line, ";") {
+				continue
+			}
+			low := strings.ToLower(line)
+			if !strings.HasPrefix(low, "endpoint") {
+				continue
+			}
+			_, val, cutOK := strings.Cut(line, "=")
+			if !cutOK {
+				_, val, cutOK = strings.Cut(line, ":")
+			}
+			if !cutOK {
+				continue
+			}
+			val = strings.TrimSpace(val)
+			if val == "" {
+				continue
+			}
+			h, p, err := net.SplitHostPort(val)
+			if err != nil {
+				return val, "51820", true
+			}
+			return h, p, true
+		}
+	}
+	return "", "", false
+}
+
 // lookupIP is overridable in tests.
 var lookupIP = defaultLookupIP