fix(panel): 建服表单按后端规则即时校验名称和子域名，控制台命令历史的下键不再跳到最早一条，补请求体测试

panel/src/lib/naming.ts

@@ -0,0 +1,31 @@
+// The server name rule (spec §2, §22) as the API enforces it in internal/naming:
+// 3–32 lowercase letters, digits or hyphens, no hyphen at either end, and none
+// of the names the platform keeps for itself. The same rule covers subdomains.
+// The create form checks it as the person types, so a name the API would
+// answer with 400 never reaches it.
+
+// RESERVED_SERVER_NAMES mirrors `reserved` in internal/naming/naming.go.
+export const RESERVED_SERVER_NAMES: readonly string[] = [
+  "login",
+  "lobby",
+  "admin",
+  "panel",
+  "console",
+  "api",
+  "felis",
+  "velocity",
+  "registry",
+  "internal",
+  "www",
+];
+
+const SERVER_NAME_RE = /^[a-z0-9-]{3,32}$/;
+
+export type ServerNameIssue = "shape" | "reserved";
+
+/** serverNameIssue says why the API would refuse this name, or null if it takes it. */
+export function serverNameIssue(name: string): ServerNameIssue | null {
+  if (!SERVER_NAME_RE.test(name) || name.startsWith("-") || name.endsWith("-")) return "shape";
+  if (RESERVED_SERVER_NAMES.includes(name)) return "reserved";
+  return null;
+}