feat: 添加每日签到功能，新增帖子排序与社区面板优化

本次提交完成了多个核心功能迭代：
1.  新增用户每日签到系统，包含签到状态查询、连续天数统计、积分累计逻辑
2.  新增"新帖子"排序选项，替换原有的latest排序为新评论排序
3.  重构首页信息流布局，优化移动端与桌面端展示样式
4.  新增最新评论、最新注册用户模块，完善社区面板数据展示
5.  新增静态友情链接配置模块
6.  提取通用时间格式化工具函数，统一全站相对时间展示
7.  补充数据库签到模型与后端API接口，完善前后端交互链路

frontend/components/PostRow.tsx

@@ -1,25 +1,11 @@
 import Link from "next/link";
 import { ArrowLeft } from "lucide-react";
 import type { PostListItem } from "@/lib/api";
+import { formatRelative } from "@/lib/format";
 import LikeButton from "./LikeButton";
 import Avatar from "./Avatar";
 import { IconComment, IconEye } from "./Icons";
 
-/** 发帖/回复时间统一为相对时间：刚刚 / N分钟前 / N小时前 / N天前 / N个月前 / N年前 */
-function formatRelative(dateStr: string) {
-  const t = new Date(dateStr).getTime();
-  const diff = Date.now() - t;
-  const min = 60_000,
-    hour = 60 * min,
-    day = 24 * hour;
-  if (diff < min) return "刚刚";
-  if (diff < hour) return `${Math.floor(diff / min)}分钟前`;
-  if (diff < day) return `${Math.floor(diff / hour)}小时前`;
-  if (diff < 30 * day) return `${Math.floor(diff / day)}天前`;
-  if (diff < 365 * day) return `${Math.floor(diff / (30 * day))}个月前`;
-  return `${Math.floor(diff / (365 * day))}年前`;
-}
-
 /**
  * 帖子列表行（参考社区信息流样式）：
  * 大头像 + 加粗标题（徽章内联）+ 第二行「板块 · 作者 · 发布时间 ← 最后回复」+
@@ -45,11 +31,13 @@ export default function PostRow({
 
   return (
     <div
-      className="group relative flex items-center gap-3.5 sm:gap-4 px-4 sm:px-5 border-t transition-colors hover:bg-[var(--panel-2)] j13-fade-up"
+      className={`group relative flex items-center px-4 sm:px-5 border-t transition-colors hover:bg-[var(--panel-2)] j13-fade-up ${
+        compact ? "gap-2.5 sm:gap-3" : "gap-3.5 sm:gap-4"
+      }`}
       style={{
         borderColor: "var(--line)",
-        paddingTop: compact ? 15 : 18,
-        paddingBottom: compact ? 15 : 18,
+        paddingTop: compact ? 11 : 18,
+        paddingBottom: compact ? 11 : 18,
         animationDelay: `${Math.min(index, 9) * 35}ms`,
       }}
     >
@@ -59,7 +47,7 @@ export default function PostRow({
         aria-label={post.user.nickname}
         tabIndex={-1}
       >
-        <Avatar name={post.user.nickname || post.user.username} size={compact ? 44 : 46} />
+        <Avatar name={post.user.nickname || post.user.username} size={compact ? 38 : 46} />
       </Link>
 
       <div className="flex-1 min-w-0">
@@ -72,14 +60,20 @@ export default function PostRow({
             aria-label={post.title}
           >
             <h3
-              className="font-bold text-[16px] sm:text-[17px] leading-snug truncate transition-colors group-hover:text-[var(--accent)]"
+              className={`font-bold leading-snug truncate transition-colors group-hover:text-[var(--accent)] ${
+                compact ? "text-[15px]" : "text-[16px] sm:text-[17px]"
+              }`}
               style={{ color: "var(--ink)" }}
             >
               {post.title}
             </h3>
           </Link>
         </div>
-        <div className="meta relative z-[2] flex items-center gap-x-2 gap-y-1 mt-1.5 flex-wrap text-[13px]">
+        <div
+          className={`meta relative z-[2] flex items-center gap-x-2 gap-y-1 flex-wrap ${
+            compact ? "mt-1 text-[12.5px]" : "mt-1.5 text-[13px]"
+          }`}
+        >
           {boardHref && (
             <Link
               href={`/board/${post.board.id}`}
@@ -109,6 +103,11 @@ export default function PostRow({
               <span className="tabular-nums shrink-0">{formatRelative(lastReply!.created_at)}</span>
             </span>
           )}
+          {!replied && post.comment_count === 0 && (
+            <span className="hidden sm:inline" aria-hidden>
+              · 暂无回复
+            </span>
+          )}
         </div>
       </div>
 

frontend/components/home/CheckinCard.tsx

@@ -0,0 +1,113 @@
+"use client";
+
+import { useState } from "react";
+import Link from "next/link";
+import { CalendarDays, CalendarCheck, LogIn, Loader2 } from "lucide-react";
+import { apiDoCheckin, type CheckinStatus } from "@/lib/api";
+
+/**
+ * 每日签到卡（右栏）。
+ * initial 为 undefined 表示游客；否则为 SSR 注入的登录用户签到状态。
+ */
+export default function CheckinCard({ initial }: { initial?: CheckinStatus | null }) {
+  const [status, setStatus] = useState<CheckinStatus | null>(initial ?? null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState("");
+
+  // 游客态
+  if (initial === undefined) {
+    return (
+      <section className="j13-module" aria-label="每日签到">
+        <div className="flex items-center gap-3">
+          <span
+            className="w-10 h-10 rounded-xl flex items-center justify-center shrink-0"
+            style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
+          >
+            <CalendarDays size={19} />
+          </span>
+          <div className="min-w-0">
+            <p className="text-[14px] font-bold" style={{ color: "var(--ink)" }}>
+              每日签到
+            </p>
+            <p className="meta text-[12px] mt-0.5">登录后每日签到领积分</p>
+          </div>
+        </div>
+        <Link href="/login?redirect=/" className="btn btn-line btn-sm w-full justify-center mt-3.5">
+          <LogIn size={14} /> 登录后签到
+        </Link>
+      </section>
+    );
+  }
+
+  const checked = status?.checked_today ?? false;
+
+  async function doCheckin() {
+    if (loading || checked) return;
+    setLoading(true);
+    setError("");
+    try {
+      setStatus(await apiDoCheckin());
+    } catch (e) {
+      setError(e instanceof Error ? e.message : "签到失败");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  return (
+    <section className="j13-module" aria-label="每日签到">
+      <div className="flex items-center gap-3">
+        <span
+          className="w-10 h-10 rounded-xl flex items-center justify-center shrink-0"
+          style={{
+            background: checked ? "var(--accent-soft)" : "var(--panel-2)",
+            color: checked ? "var(--accent)" : "var(--ink-2)",
+          }}
+        >
+          {checked ? <CalendarCheck size={19} /> : <CalendarDays size={19} />}
+        </span>
+        <div className="flex-1 min-w-0">
+          <p className="text-[14px] font-bold" style={{ color: "var(--ink)" }}>
+            每日签到
+          </p>
+          <p className="meta text-[12px] mt-0.5">
+            {checked
+              ? `已连续签到 ${status?.streak ?? 0} 天 · 累计 ${status?.total_points ?? 0} 积分`
+              : `连续 ${status?.streak ?? 0} 天 · 今日可得 ${status?.today_points ?? 5} 积分`}
+          </p>
+        </div>
+        {!checked && (
+          <span className="text-[17px] font-extrabold tabular-nums shrink-0" style={{ color: "var(--accent)" }}>
+            +{status?.today_points ?? 5}
+          </span>
+        )}
+      </div>
+
+      <button
+        type="button"
+        onClick={doCheckin}
+        disabled={loading || checked}
+        aria-disabled={loading || checked}
+        className={`btn w-full justify-center mt-3.5 ${checked ? "btn-line" : "btn-primary"}`}
+      >
+        {loading ? (
+          <>
+            <Loader2 size={15} className="animate-spin" /> 签到中…
+          </>
+        ) : checked ? (
+          <>
+            <CalendarCheck size={15} /> 今日已签到
+          </>
+        ) : (
+          "立即签到"
+        )}
+      </button>
+
+      {error && (
+        <p className="text-[12px] mt-2" style={{ color: "var(--clay)" }} role="alert">
+          {error}
+        </p>
+      )}
+    </section>
+  );
+}

frontend/components/home/CommunityPanels.tsx

@@ -1,7 +1,106 @@
 import Link from "next/link";
-import { Flame, Users, MessageCircle, Heart } from "lucide-react";
-import type { PostListItem, ActiveUser } from "@/lib/api";
+import {
+  Flame,
+  Users,
+  MessageCircle,
+  Heart,
+  MessageSquareText,
+  UserPlus,
+  Link2,
+} from "lucide-react";
+import type {
+  PostListItem,
+  ActiveUser,
+  OverviewStats,
+  LatestComment,
+  NewUser,
+  CheckinStatus,
+} from "@/lib/api";
 import Avatar from "@/components/Avatar";
+import CheckinCard from "./CheckinCard";
+import { FRIEND_LINKS } from "@/lib/friendLinks";
+import { formatRelative } from "@/lib/format";
+
+/* ---------- 品牌卡 ---------- */
+
+function BrandCard({ stats }: { stats: OverviewStats }) {
+  const items: { num: number; label: string }[] = [
+    { num: stats.posts, label: "帖子" },
+    { num: stats.comments, label: "回复" },
+    { num: stats.users, label: "用户" },
+  ];
+  return (
+    <section className="j13-module text-center" aria-label="姜十三论坛">
+      <p className="text-[16.5px] font-extrabold tracking-wide" style={{ color: "var(--accent)" }}>
+        姜十三论坛
+      </p>
+      <p className="meta mt-1 text-[12px]">分享技术、讨论问题、交流心得</p>
+      <div
+        className="mt-3.5 pt-3.5 grid grid-cols-3"
+        style={{ borderTop: "1px solid var(--line)" }}
+      >
+        {items.map((it) => (
+          <div key={it.label}>
+            <p
+              className="text-[19px] font-extrabold tabular-nums leading-none"
+              style={{ color: "var(--accent)" }}
+            >
+              {it.num}
+            </p>
+            <p className="meta mt-1.5 text-[11.5px]">{it.label}</p>
+          </div>
+        ))}
+      </div>
+    </section>
+  );
+}
+
+/* ---------- 最新评论 ---------- */
+
+function LatestComments({ comments }: { comments: LatestComment[] }) {
+  if (comments.length === 0) return null;
+  return (
+    <section className="j13-module" aria-label="最新评论">
+      <p className="j13-module-title mb-1">
+        <MessageSquareText size={15} style={{ color: "var(--accent)" }} /> 最新评论
+      </p>
+      <ul>
+        {comments.map((c) => {
+          const name = c.user.nickname || c.user.username;
+          return (
+            <li key={c.id}>
+              <Link href={`/post/${c.post.id}`} className="j13-raillink items-start">
+                <Avatar name={name} src={c.user.avatar} size={28} className="mt-px" />
+                <span className="min-w-0 flex-1">
+                  <span className="flex items-baseline gap-1.5">
+                    <span
+                      className="shrink-0 max-w-[84px] truncate text-[12.5px] font-semibold"
+                      style={{ color: "var(--ink-2)" }}
+                    >
+                      {name}
+                    </span>
+                    <span
+                      className="min-w-0 flex-1 truncate text-[13px]"
+                      style={{ color: "var(--ink-2)" }}
+                    >
+                      {c.content}
+                    </span>
+                  </span>
+                  <span className="meta mt-0.5 block truncate text-[11.5px]">
+                    {c.post.title}
+                  </span>
+                </span>
+                <span className="meta mt-px shrink-0 text-[11px]">
+                  {formatRelative(c.created_at)}
+                </span>
+              </Link>
+            </li>
+          );
+        })}
+      </ul>
+    </section>
+  );
+}
 
 /* ---------- 热门榜 ---------- */
 
@@ -45,6 +144,41 @@ function HotRanking({ posts }: { posts: PostListItem[] }) {
   );
 }
 
+/* ---------- 最新注册 ---------- */
+
+function NewUsers({ users }: { users: NewUser[] }) {
+  if (users.length === 0) return null;
+  return (
+    <section className="j13-module" aria-label="最新注册">
+      <p className="j13-module-title mb-3">
+        <UserPlus size={15} style={{ color: "var(--accent)" }} /> 最新注册
+      </p>
+      <ul className="grid grid-cols-4 gap-y-3">
+        {users.map((u) => {
+          const name = u.nickname || u.username;
+          return (
+            <li key={u.id}>
+              <Link
+                href={`/u/${u.id}`}
+                className="flex flex-col items-center gap-1.5 rounded-lg px-1 py-1 transition-colors hover:bg-[var(--panel-2)]"
+              >
+                <Avatar name={name} src={u.avatar} size={38} />
+                <span
+                  className="w-full truncate text-center text-[11px]"
+                  style={{ color: "var(--ink-2)" }}
+                  title={name}
+                >
+                  {name}
+                </span>
+              </Link>
+            </li>
+          );
+        })}
+      </ul>
+    </section>
+  );
+}
+
 /* ---------- 活跃用户 ---------- */
 
 function ActiveUsers({ users }: { users: ActiveUser[] }) {
@@ -73,20 +207,72 @@ function ActiveUsers({ users }: { users: ActiveUser[] }) {
   );
 }
 
+/* ---------- 友情链接 ---------- */
+
+function FriendLinks() {
+  return (
+    <section className="j13-module" aria-label="友情链接">
+      <p className="j13-module-title mb-3">
+        <Link2 size={15} style={{ color: "var(--accent)" }} /> 友情链接
+        <Link
+          href="/compose"
+          className="meta ml-auto text-[12px] font-normal transition-colors hover:text-[var(--accent)]"
+        >
+          申请
+        </Link>
+      </p>
+      <div className="flex flex-wrap gap-2">
+        {FRIEND_LINKS.map((l) =>
+          l.href.startsWith("http") ? (
+            <a
+              key={l.name}
+              href={l.href}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="j13-chip"
+            >
+              {l.name}
+            </a>
+          ) : (
+            <span key={l.name} className="j13-chip" title="友链待配置">
+              {l.name}
+            </span>
+          )
+        )}
+      </div>
+    </section>
+  );
+}
+
 /* ---------- 桌面 / 移动两种装配 ---------- */
 
-export function CommunityPanels({
-  hot,
-  activeUsers,
-}: {
+type PanelsProps = {
+  stats: OverviewStats;
   hot: PostListItem[];
   activeUsers: ActiveUser[];
-}) {
+  latestComments: LatestComment[];
+  newUsers: NewUser[];
+  checkin?: CheckinStatus | null;
+};
+
+export function CommunityPanels({
+  stats,
+  hot,
+  activeUsers,
+  latestComments,
+  newUsers,
+  checkin,
+}: PanelsProps) {
   return (
-    <aside className="hidden lg:block w-[280px] xl:w-[300px] shrink-0" aria-label="社区面板">
+    <aside className="hidden w-[280px] shrink-0 lg:block xl:w-[300px]" aria-label="社区面板">
       <div className="sticky top-24 space-y-4">
+        <BrandCard stats={stats} />
+        <CheckinCard initial={checkin} />
+        <LatestComments comments={latestComments} />
         <HotRanking posts={hot} />
+        <NewUsers users={newUsers} />
         <ActiveUsers users={activeUsers} />
+        <FriendLinks />
       </div>
     </aside>
   );
@@ -95,14 +281,18 @@ export function CommunityPanels({
 export function CommunityPanelsMobile({
   hot,
   activeUsers,
-}: {
-  hot: PostListItem[];
-  activeUsers: ActiveUser[];
-}) {
+  latestComments,
+  newUsers,
+  checkin,
+}: Omit<PanelsProps, "stats">) {
   return (
-    <div className="lg:hidden space-y-4" aria-label="社区面板">
+    <div className="space-y-4 lg:hidden" aria-label="社区面板">
+      <CheckinCard initial={checkin} />
+      <LatestComments comments={latestComments} />
       <HotRanking posts={hot} />
+      <NewUsers users={newUsers} />
       <ActiveUsers users={activeUsers} />
+      <FriendLinks />
     </div>
   );
 }

frontend/components/home/FeedTabs.tsx

@@ -3,15 +3,11 @@
 import Link from "next/link";
 import { useRouter } from "next/navigation";
 import { useRef } from "react";
+import { MessageSquareText, Clock, Sparkles } from "lucide-react";
 
-export type FeedSort = "latest" | "hot" | "recommended";
+export type FeedSort = "latest" | "new" | "recommended";
 
-const TAB_KEYS: FeedSort[] = ["latest", "hot", "recommended"];
-const TAB_LABELS: Record<FeedSort, string> = {
-  latest: "最新",
-  hot: "热门",
-  recommended: "精华",
-};
+const TAB_KEYS: FeedSort[] = ["latest", "new", "recommended"];
 
 // 在指定板块内切换排序时保留 ?board=
 function tabHref(key: FeedSort, boardId: number) {
@@ -36,22 +32,27 @@ export default function FeedTabs({ current, boardId = 0 }: { current: FeedSort;
   };
 
   return (
-    <div className="j13-seg" role="tablist" aria-label="帖子排序">
-      {TAB_KEYS.map((key, i) => (
-        <Link
-          key={key}
-          ref={(el) => {
-            tabRefs.current[i] = el;
-          }}
-          href={tabHref(key, boardId)}
-          role="tab"
-          aria-selected={current === key}
-          tabIndex={current === key ? 0 : -1}
-          onKeyDown={(e) => handleKeyDown(e, i)}
-        >
-          {TAB_LABELS[key]}
-        </Link>
-      ))}
+    <div className="flex items-center gap-1.5 sm:gap-2" role="tablist" aria-label="帖子排序">
+      {TAB_KEYS.map((key, i) => {
+        const Icon = key === "latest" ? MessageSquareText : key === "new" ? Clock : Sparkles;
+        return (
+          <Link
+            key={key}
+            ref={(el) => {
+              tabRefs.current[i] = el;
+            }}
+            href={tabHref(key, boardId)}
+            role="tab"
+            className="j13-tab inline-flex items-center gap-1"
+            aria-selected={current === key}
+            tabIndex={current === key ? 0 : -1}
+            onKeyDown={(e) => handleKeyDown(e, i)}
+          >
+            <Icon size={13} className="opacity-80" />
+            {key === "latest" ? "新评论" : key === "new" ? "新帖子" : "推荐帖"}
+          </Link>
+        );
+      })}
     </div>
   );
 }

frontend/components/home/HomeHero.tsx

@@ -1,76 +0,0 @@
-import Link from "next/link";
-import { PenSquare, LogIn, UserPlus, MessagesSquare, Users, MessageCircle, Sparkles } from "lucide-react";
-import type { OverviewStats } from "@/lib/api";
-
-type HeroUser = { username: string; nickname: string } | null;
-
-function greetingOf(h: number): string {
-  if (h >= 5 && h < 11) return "早上好";
-  if (h >= 11 && h < 14) return "中午好";
-  if (h >= 14 && h < 18) return "下午好";
-  if (h >= 18 && h < 23) return "晚上好";
-  return "夜深了";
-}
-
-// 首页欢迎横幅：时段问候 + 站点主张 + 发帖引导 + 内联社区数据。纯服务端组件。
-export default function HomeHero({ user, stats }: { user: HeroUser; stats: OverviewStats | null }) {
-  const name = user ? user.nickname || user.username : null;
-  const hello = greetingOf(new Date().getHours());
-  const today = stats?.today_posts ?? 0;
-
-  const statItems = stats
-    ? [
-        { icon: MessagesSquare, label: "讨论", value: stats.posts, hot: false },
-        { icon: Users, label: "成员", value: stats.users, hot: false },
-        { icon: MessageCircle, label: "评论", value: stats.comments, hot: false },
-        { icon: Sparkles, label: today > 0 ? "今日新帖" : "今日", value: today, hot: today > 0 },
-      ]
-    : [];
-
-  return (
-    <section className="j13-hero mb-5 lg:mb-6" aria-label="欢迎">
-      <span aria-hidden className="j13-hero-glow" />
-      <div className="relative flex flex-col lg:flex-row lg:items-center lg:justify-between gap-5">
-        <div className="min-w-0">
-          <p className="meta text-[13px]">{name ? `${hello}，${name}` : `${hello}，欢迎来到姜十三`}</p>
-          <h2
-            className="mt-1.5 text-[19px] sm:text-[22px] font-extrabold tracking-tight"
-            style={{ color: "var(--ink)" }}
-          >
-            分享技术、讨论问题、交流心得
-          </h2>
-          <div className="mt-4 flex flex-wrap gap-2.5">
-            {user ? (
-              <Link href="/compose" className="btn btn-primary w-full sm:w-auto justify-center">
-                <PenSquare size={15} /> 发起讨论
-              </Link>
-            ) : (
-              <>
-                <Link href="/login?redirect=/" className="btn btn-primary w-full sm:w-auto justify-center">
-                  <LogIn size={15} /> 登录后参与讨论
-                </Link>
-                <Link href="/register" className="btn btn-line w-full sm:w-auto justify-center">
-                  <UserPlus size={15} /> 注册
-                </Link>
-              </>
-            )}
-          </div>
-        </div>
-
-        {statItems.length > 0 && (
-          <dl className="j13-hero-stats shrink-0" aria-label="社区数据">
-            {statItems.map(({ icon: Icon, label, value, hot }) => (
-              <div key={label} className="j13-hero-stat">
-                <dd className={`j13-hero-stat-num${hot ? " is-hot" : ""}`}>{value}</dd>
-                <dt className="j13-hero-stat-lab">
-                  {hot && <span className="j13-dot-pulse" aria-hidden />}
-                  <Icon size={12} /> {label}
-                </dt>
-              </div>
-            ))}
-          </dl>
-        )}
-      </div>
-    </section>
-  );
-}