polish(frontend): 侧栏与徽章可读性，智能悬停提示

降权全站字重；优化右栏公告/数据块；类型状态徽章用固定浅色区分；TipHost 仅在文案不一致、非文字或省略时显示。

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

frontend/components/NotificationBell.tsx

@@ -168,7 +168,7 @@ export default function NotificationBell({ initialUnread = 0 }: { initialUnread?
         <Bell size={17} />
         {unread > 0 && (
           <span
-            className="absolute -top-1 -right-1 min-w-[18px] h-[18px] px-1 text-[10px] font-bold flex items-center justify-center rounded-full"
+            className="absolute -top-1 -right-1 min-w-[18px] h-[18px] px-1 text-[10px] font-medium flex items-center justify-center rounded-full"
             style={{
               background: "var(--clay)",
               color: "#fff",
@@ -194,7 +194,7 @@ export default function NotificationBell({ initialUnread = 0 }: { initialUnread?
             className="flex items-center justify-between px-5 py-3.5"
             style={{ borderBottom: "1px solid var(--line)" }}
           >
-            <span className="font-bold text-[15px]" style={{ color: "var(--ink)" }}>通知</span>
+            <span className="font-semibold text-[15px]" style={{ color: "var(--ink)" }}>通知</span>
             {unread > 0 && (
               <button
                 onClick={handleMarkAllRead}
@@ -238,7 +238,7 @@ export default function NotificationBell({ initialUnread = 0 }: { initialUnread?
                     <p className="text-sm leading-snug" style={{ color: "var(--ink)" }}>
                       {approval ? (
                         <span
-                          className="font-bold"
+                          className="font-medium"
                           style={{ color: n.type === "approved" ? "var(--ok)" : "var(--danger)" }}
                         >
                           {actionText(n)}