feat(auth): 注册服务协议 - 名称与条款改为后台可配置并同步注册页展示

后端：
- RegistrationSettingRequest 协议字段改为可选指针，注册开关单独保存不再覆盖协议正文
- 新增 RegistrationAgreement / AgreementTitleForMessage：标题未配置时跟随品牌名生成，读取失败返回空标题而非猜一个不存在的协议名
- PublicAuthSettings 下发 agreementTitle / agreementContent，首用户分支同样携带
- 新增 registration_agreement_test.go 覆盖品牌名兜底、存储合并与失败降级

前端：
- 注册页协议标题与条款改为消费后台配置；读取失败时隐藏协议入口并支持重新读取
- 验证码获取按钮内联到输入框右侧，联系方式为空即禁用；sms_email 双通道合并为单输入框
- 协议弹窗重排：条目标题独立成行加重、空态虚线提示、底部补充同意说明；深浅主题适配
- 协议勾选行改为状态化区域，复选框适配 AntD 6 结构（方框在 .ant-checkbox 本体，修正深色主题白底白勾）
- 后台「服务协议名称与条款」区块补齐表单内边距并对齐区块头/页脚，协议名称限宽

文档：http-api.mdx 更新协议字段语义与失败降级说明；pending-test.mdx 增加手工验证清单

web/src/pages/auth/register.tsx

@@ -1,6 +1,6 @@
 import { type FormEvent, useEffect, useRef, useState, type ReactNode } from "react";
 import { App, Button, Checkbox, Divider, Input, Modal, Segmented } from "antd";
-import { ArrowRight, Info, LockKeyhole, Mail, TriangleAlert, UserRound } from "lucide-react";
+import { ArrowRight, FileText, Info, LockKeyhole, Mail, TriangleAlert, UserRound } from "lucide-react";
 import { useNavigate, useSearchParams } from "react-router";
 
 import { getAuthSession, getAuthSettings, linuxDOLoginURL, register } from "@/services/api/auth";
@@ -8,16 +8,15 @@ import { LinuxDOIcon } from "./auth-scene";
 import { ApiError } from "@/services/api/request";
 import { VerificationFields } from "@/components/auth/verification-fields";
 import { emptyVerification, methodLabels, verificationMethods, type VerificationMethod } from "@/services/api/verification";
+import { useAppearanceStore } from "@/stores/use-appearance-store";
 
 type AuthSettings = Awaited<ReturnType<typeof getAuthSettings>>;
 
-// TODO: 由维护者填写正式的影策服务协议条款后再发布。
-const SERVICE_AGREEMENT: { title: string; content: string }[] = [];
-
 export default function RegisterPage() {
     const navigate = useNavigate();
     const [params] = useSearchParams();
     const { message } = App.useApp();
+    const brandName = useAppearanceStore((state) => state.appearance.brandName) || "平台";
     const [settings, setSettings] = useState<AuthSettings | null>(null);
     const [username, setUsername] = useState("");
     const [email, setEmail] = useState("");
@@ -28,26 +27,43 @@ export default function RegisterPage() {
     const [confirmPassword, setConfirmPassword] = useState("");
     const [agreementAccepted, setAgreementAccepted] = useState(false);
     const [agreementOpen, setAgreementOpen] = useState(false);
+    const [settingsFailed, setSettingsFailed] = useState(false);
+    const [settingsReloadKey, setSettingsReloadKey] = useState(0);
     const [submitting, setSubmitting] = useState(false);
     const [registerCountdown, setRegisterCountdown] = useState(0);
     const registering = useRef(false);
     const next = safeNext(params.get("next"));
 
+    // 协议标题与条款由后台「登录与注册」配置下发。标题未配置时才回退到当前品牌名，
+    // 且只在确认拿到设置（settings 非空）后回退；接口失败时不猜标题，避免展示
+    // 与后台真实配置不符的协议名。
+    // 标题统一去掉书号后由页面补《》，避免后台已填《》时出现双书名号。
+    const agreementTitle = ((settings?.agreementTitle || "").trim() || `${brandName}服务协议`).replace(/^《|》$/g, "");
+    const agreementContent = (settings?.agreementContent || "").trim();
+    const agreementParagraphs = agreementContent ? agreementContent.split(/\n\s*\n/) : [];
+
     useEffect(() => {
         let cancelled = false;
+        setSettingsFailed(false);
         void getAuthSettings()
             .then((value) => { if (!cancelled) { setSettings(value); setMethod(verificationMethods(value, "register")[0] ?? "email"); } })
-            .catch((error) => !cancelled && message.error(error instanceof Error ? error.message : "读取注册设置失败"));
+            .catch((error) => {
+                if (cancelled) return;
+                // 这里必须留下失败态：协议标题只能来自后台配置，读不到时不能用品牌名
+                // 顶替，否则用户看到的是一个后台并不存在的协议名称。
+                setSettingsFailed(true);
+                message.error(error instanceof Error ? error.message : "读取注册设置失败");
+            });
         return () => {
             cancelled = true;
         };
-    }, [message]);
+    }, [message, settingsReloadKey]);
 
     const submit = async (event: FormEvent<HTMLFormElement>) => {
         event.preventDefault();
         if (registering.current || registerCountdown > 0) return;
         if (!agreementAccepted) {
-            message.warning("请先同意影策服务协议");
+            message.warning(`请先同意${agreementTitle}`);
             return;
         }
         if (password !== confirmPassword) {
@@ -154,14 +170,27 @@ export default function RegisterPage() {
                 </AuthField>
             </div>
 
-            <div className="auth-scene-muted flex items-start gap-2 text-xs leading-5">
-                <Checkbox checked={agreementAccepted} onChange={(event) => setAgreementAccepted(event.target.checked)}>
-                    <span className="auth-scene-muted text-xs leading-5">我已阅读并同意</span>
-                </Checkbox>
-                <button type="button" className="auth-scene-link -ml-1 text-xs leading-5 transition" onClick={() => setAgreementOpen(true)}>
-                    《影策服务协议》
-                </button>
-            </div>
+            {settingsFailed ? (
+                <Notice icon={<TriangleAlert className="size-3.5" />} tone="amber">
+                    <span>
+                        读取注册设置失败，暂时无法确认服务协议名称与条款。
+                        <button type="button" className="auth-scene-link ml-1 transition" onClick={() => setSettingsReloadKey((value) => value + 1)}>
+                            重新读取
+                        </button>
+                    </span>
+                </Notice>
+            ) : null}
+
+            {settings ? (
+                <div className="auth-agreement-row" data-accepted={agreementAccepted ? "true" : "false"}>
+                    <Checkbox checked={agreementAccepted} onChange={(event) => setAgreementAccepted(event.target.checked)}>
+                        <span className="auth-agreement-label">我已阅读并同意</span>
+                    </Checkbox>
+                    <button type="button" className="auth-agreement-link" onClick={() => setAgreementOpen(true)}>
+                        《{agreementTitle}》
+                    </button>
+                </div>
+            ) : null}
 
             <Button type="primary" htmlType="submit" size="large" block loading={submitting} disabled={disabled || registerCountdown > 0 || !agreementAccepted} icon={<ArrowRight className="size-4" />} iconPlacement="end">
                 {registerCountdown > 0 ? `${registerCountdown} 秒后可重试` : "创建账号"}
@@ -176,16 +205,38 @@ export default function RegisterPage() {
                     </Button>
                 </>
             ) : null}
-            <Modal className="workspace-modal workspace-modal-compact" title="影策服务协议" open={agreementOpen} onCancel={() => setAgreementOpen(false)} footer={null} destroyOnHidden>
-                <div className="max-h-96 space-y-4 overflow-y-auto pr-1 text-sm leading-6 text-foreground/68">
-                    {SERVICE_AGREEMENT.length === 0 ? <p className="m-0">服务协议内容待补充。</p> : null}
-                    {SERVICE_AGREEMENT.map((item) => (
-                        <section key={item.title}>
-                            <h3 className="m-0 text-sm font-semibold text-foreground">{item.title}</h3>
-                            <p className="mt-1.5 mb-0">{item.content}</p>
-                        </section>
-                    ))}
-                </div>
+            <Modal
+                className="workspace-modal workspace-modal-compact auth-agreement-modal"
+                title={agreementTitle}
+                open={agreementOpen}
+                onCancel={() => setAgreementOpen(false)}
+                footer={null}
+                destroyOnHidden
+            >
+                {agreementParagraphs.length === 0 ? (
+                    <div className="auth-agreement-empty">
+                        <FileText className="size-3.5 shrink-0" aria-hidden />
+                        服务协议内容待补充，请联系管理员在后台「登录与注册」中完善。
+                    </div>
+                ) : (
+                    <div className="auth-agreement-body">
+                        {agreementParagraphs.map((paragraph, index) => {
+                            // 后台用纯文本框维护条款，「一、二、三…」条目通常和正文写在同一个
+                            // 段落里（只用一个换行分隔）。这里把条目标题切出来单独成行并加重，
+                            // 否则标题和正文会挤在同一行，长条款失去可扫描的层级。
+                            const blocks = splitAgreementParagraph(paragraph);
+                            return blocks.map((block, blockIndex) => (
+                                <p key={`agreement-${index}-${blockIndex}`} data-role={block.heading ? "heading" : undefined}>
+                                    {block.text}
+                                </p>
+                            ));
+                        })}
+                    </div>
+                )}
+                <p className="auth-agreement-meta">
+                    <LockKeyhole className="size-3 shrink-0" aria-hidden />
+                    继续注册即表示你已阅读并接受本协议全部条款。
+                </p>
             </Modal>
         </form>
     );
@@ -213,3 +264,20 @@ function safeNext(value: string | null) {
     if (!value || !value.startsWith("/") || value.startsWith("//")) return "/";
     return value;
 }
+
+// 中文条款里「一、」「二、」这类条目标题常与正文写在同一个段落内（只隔一个换行）。
+// 这里按「条目标题 + 紧随其后的正文」拆成独立段落，让标题能单独成行并加重；
+// 没有条目标题的普通段落原样返回，不改变后台已经整理好的排版。
+const AGREEMENT_HEADING = /^\s*([一二三四五六七八九十百]+、[^\n]{0,40})\n+([\s\S]+)$/;
+
+function splitAgreementParagraph(paragraph: string): { text: string; heading: boolean }[] {
+    const match = paragraph.match(AGREEMENT_HEADING);
+    if (!match) {
+        const headingOnly = /^\s*[一二三四五六七八九十百]+、[^\n]{0,40}\s*$/.test(paragraph);
+        return [{ text: paragraph.trim(), heading: headingOnly }];
+    }
+    return [
+        { text: match[1].trim(), heading: true },
+        { text: match[2].trim(), heading: false },
+    ];
+}