fix(api): 服务器显示名称限 64 个可见字符，拒绝换行、控制符和不可见格式符

internal/naming/naming.go

@@ -9,6 +9,8 @@ import (
 	"fmt"
 	"regexp"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 )
 
 var (
@@ -145,6 +147,33 @@ func ValidateSystemServerName(name string) error {
 	return nil
 }
 
+// zeroWidthJoiner (U+200D) glues emoji such as the rainbow flag into one picture.
+const zeroWidthJoiner = 0x200D
+
+// MaxDisplayName is the most characters a server's display name may have. The
+// panel shows it on one line in the fleet grid and the server header.
+const MaxDisplayName = 64
+
+// CleanDisplayName trims a server's display name and checks what is left: at most
+// MaxDisplayName characters, every one a visible character or a space. Control
+// characters, line breaks and the invisible format characters (bidi overrides,
+// zero-width spaces) are refused, since they would break the line the panel puts
+// the name on or make it read as something else; the zero-width joiner stays,
+// because emoji such as the rainbow flag are built with it. An empty result is
+// valid: the server then goes by its name.
+func CleanDisplayName(s string) (string, error) {
+	s = strings.TrimSpace(s)
+	if n := utf8.RuneCountInString(s); n > MaxDisplayName {
+		return "", fmt.Errorf("naming: display name has %d characters, at most %d are allowed", n, MaxDisplayName)
+	}
+	for _, r := range s {
+		if r == utf8.RuneError || !unicode.IsGraphic(r) && r != zeroWidthJoiner {
+			return "", fmt.Errorf("naming: display name contains %U, which is not a visible character", r)
+		}
+	}
+	return s, nil
+}
+
 // worldVolumeName mirrors operator.dataVolumeName: the per-server StatefulSet's
 // volumeClaimTemplate is named "world", so a single-replica server's world PVC
 // is "world-<name>-0". This is the one naming convention shared by the operator

internal/naming/naming_test.go

@@ -149,3 +149,41 @@ func TestValidateHostname(t *testing.T) {
 		t.Error("ValidateHostname should reject an empty root domain")
 	}
 }
+
+func TestCleanDisplayName(t *testing.T) {
+	str := func(rs ...rune) string { return string(rs) }
+	rainbow := str(0x1F3F3, 0xFE0F, 0x200D, 0x1F308)
+	cjk := func(n int) string {
+		s := ""
+		for range n {
+			s += "生"
+		}
+		return s
+	}
+	for _, c := range []struct {
+		name, in, want string
+		ok             bool
+	}{
+		{"trimmed", "  Survival World  ", "Survival World", true},
+		{"empty", "", "", true},
+		{"only spaces", "   ", "", true},
+		{"cjk and punctuation", "生存服 · 第二季!", "生存服 · 第二季!", true},
+		{"emoji joined by zwj", "Pride " + rainbow, "Pride " + rainbow, true},
+		{"ideographic space inside", "生存" + str(0x3000) + "服", "生存" + str(0x3000) + "服", true},
+		{"64 characters of 3 bytes each", cjk(64), cjk(64), true},
+		{"65 characters", cjk(65), "", false},
+		{"tab", "a" + str(0x09) + "b", "", false},
+		{"newline", "a" + str(0x0A) + "b", "", false},
+		{"nul", "a" + str(0x00), "", false},
+		{"right-to-left override", "abc" + str(0x202E) + "exe.txt", "", false},
+		{"zero-width space", "ad" + str(0x200B) + "min", "", false},
+		{"line separator", "a" + str(0x2028) + "b", "", false},
+		{"private use", "a" + str(0xE000), "", false},
+		{"invalid utf-8", string([]byte{'a', 0xff}), "", false},
+	} {
+		got, err := naming.CleanDisplayName(c.in)
+		if (err == nil) != c.ok || got != c.want {
+			t.Errorf("%s: CleanDisplayName(%q) = %q, %v; want %q, ok=%v", c.name, c.in, got, err, c.want, c.ok)
+		}
+	}
+}

internal/naming/panel_mirror_test.go

@@ -1,6 +1,7 @@
 package naming
 
 import (
+	"fmt"
 	"os"
 	"regexp"
 	"slices"
@@ -11,7 +12,8 @@ import (
 // The panel's create form checks names as they are typed with its own copy of
 // this rule (panel/src/lib/naming.ts). A name reserved or a length changed here
 // without the panel would let the form send what the API refuses, or refuse what
-// it takes, so the copy is compared to the source.
+// it takes, so the copy is compared to the source. The copy also holds the display-name
+// length the create and edit forms stop at.
 func TestPanelMirrorsServerNameRule(t *testing.T) {
 	raw, err := os.ReadFile("../../panel/src/lib/naming.ts")
 	if err != nil {
@@ -40,4 +42,7 @@ func TestPanelMirrorsServerNameRule(t *testing.T) {
 	if want := "const SERVER_NAME_RE = /" + serverNameRE.String() + "/;"; !strings.Contains(src, want) {
 		t.Errorf("panel/src/lib/naming.ts lacks %q", want)
 	}
+	if want := fmt.Sprintf("export const DISPLAY_NAME_MAX = %d;", MaxDisplayName); !strings.Contains(src, want) {
+		t.Errorf("panel/src/lib/naming.ts lacks %q", want)
+	}
 }