feat: 新增「喝什么」场景，支持奶茶/咖啡/酒吧等饮品店搜索

引入场景系统(SceneType)，首页增加「吃什么」「喝什么」切换 Tab，
不同场景使用不同的高德 POI 类型、热门标签、价格区间和全链路文案。
场景信息存储在房间数据中，邀请/分享/匹配结果等页面自动适配。

src/app/page.tsx

@@ -7,7 +7,8 @@ import { Plus, LogIn, Loader2, MapPin, Navigation, X, Users, Heart, Sparkles, Ch
 import { getUserId, getCachedProfile, getCachedPreferences } from "@/lib/userId";
 import { getAvatarBg } from "@/lib/avatars";
 import AuthModal from "@/components/AuthModal";
-import type { UserProfile } from "@/types";
+import { SCENES, getSceneConfig } from "@/lib/sceneConfig";
+import type { UserProfile, SceneType } from "@/types";
 
 interface LocationSuggestion {
   id: string;
@@ -26,15 +27,6 @@ const DISTANCE_OPTIONS = [
   { label: "5km", value: 5000 },
 ] as const;
 
-const PRICE_OPTIONS = [
-  { label: "不限", value: "any" },
-  { label: "¥50以下", value: "under50" },
-  { label: "¥50-100", value: "50to100" },
-  { label: "¥100+", value: "over100" },
-] as const;
-
-const HOT_CUISINES = ["火锅", "日料", "烧烤", "西餐", "川菜", "咖啡甜品", "小吃快餐"] as const;
-
 type GpsResult =
   | { ok: true; lat: number; lng: number }
   | { ok: false; reason: "unsupported" | "denied" | "timeout" | "unknown" };
@@ -95,6 +87,9 @@ export default function LandingPage() {
   const [gpsCoords, setGpsCoords] = useState<{ lat: number; lng: number } | null>(null);
   const [gpsLocationName, setGpsLocationName] = useState<string | null>(null);
 
+  const [scene, setScene] = useState<SceneType>("eat");
+  const sceneConfig = getSceneConfig(scene);
+
   const [profile, setProfile] = useState<UserProfile | null>(null);
   const [authModalOpen, setAuthModalOpen] = useState(false);
 
@@ -108,6 +103,12 @@ export default function LandingPage() {
     if (prefs.radius) setRadius(prefs.radius);
   }, []);
 
+  const handleSceneChange = useCallback((s: SceneType) => {
+    setScene(s);
+    setCuisine("");
+    setPriceRange("any");
+  }, []);
+
   const doGpsLocate = useCallback(async () => {
     setGpsStatus("locating");
     const result = await requestGps();
@@ -208,12 +209,12 @@ export default function LandingPage() {
     setLoading(true);
 
     try {
-      setLoadingText("正在搜索周边美食...");
+      setLoadingText(sceneConfig.loadingText);
 
       const res = await fetch("/api/room/create", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ ...coords, radius, priceRange, cuisine, userId: getUserId() }),
+        body: JSON.stringify({ ...coords, radius, priceRange, cuisine, userId: getUserId(), scene }),
       });
 
       const data = await res.json();
@@ -289,7 +290,7 @@ export default function LandingPage() {
           别说随便
         </p>
         <p className="mt-3 max-w-xs text-center text-sm leading-relaxed text-zinc-500">
-          和朋友一起滑卡片，再也不用纠结吃什么
+          {sceneConfig.subtitle}
         </p>
       </motion.div>
 
@@ -329,7 +330,34 @@ export default function LandingPage() {
       </motion.div>
 
       <motion.div
-        className="mt-10 flex w-full max-w-xs flex-col gap-3"
+        className="mt-8 flex items-center justify-center gap-2"
+        initial={{ y: 10, opacity: 0 }}
+        animate={{ y: 0, opacity: 1 }}
+        transition={{ duration: 0.4, delay: 0.12 }}
+      >
+        {SCENES.map((s) => {
+          const cfg = getSceneConfig(s);
+          const active = scene === s;
+          return (
+            <button
+              key={s}
+              onClick={() => handleSceneChange(s)}
+              disabled={loading}
+              className={`flex items-center gap-1.5 rounded-full px-4 py-2 text-sm font-semibold transition-all disabled:opacity-50 ${
+                active
+                  ? "bg-emerald-500 text-white shadow-md shadow-emerald-200"
+                  : "bg-zinc-100 text-zinc-500 hover:bg-zinc-200"
+              }`}
+            >
+              <span className="text-base leading-none">{cfg.emoji}</span>
+              {cfg.label}
+            </button>
+          );
+        })}
+      </motion.div>
+
+      <motion.div
+        className="mt-5 flex w-full max-w-xs flex-col gap-3"
         initial={{ y: 20, opacity: 0 }}
         animate={{ y: 0, opacity: 1 }}
         transition={{ duration: 0.5, delay: 0.15 }}
@@ -438,11 +466,11 @@ export default function LandingPage() {
 
         <div className="flex flex-col gap-2 rounded-xl border border-zinc-100 bg-zinc-50/50 px-3 py-2.5">
           <div className="flex items-center gap-3">
-            <span className="w-8 shrink-0 text-xs font-medium text-zinc-400">美食</span>
+            <span className="w-8 shrink-0 text-xs font-medium text-zinc-400">{sceneConfig.tagLabel}</span>
             <div className="relative flex flex-1 items-center">
               <input
                 type="text"
-                placeholder="想吃什么？（留空则不限）"
+                placeholder={sceneConfig.tagPlaceholder}
                 value={cuisine}
                 onChange={(e) => setCuisine(e.target.value)}
                 disabled={loading}
@@ -463,7 +491,7 @@ export default function LandingPage() {
             <span className="w-8 shrink-0 text-xs font-medium text-zinc-400"></span>
             <div className="flex flex-wrap items-center gap-1.5">
               <Flame size={11} className="shrink-0 text-orange-400" />
-              {HOT_CUISINES.map((tag) => (
+              {sceneConfig.hotTags.map((tag) => (
                 <button
                   key={tag}
                   type="button"
@@ -505,7 +533,7 @@ export default function LandingPage() {
           <div className="flex items-center gap-3">
             <span className="w-8 shrink-0 text-xs font-medium text-zinc-400">人均</span>
             <div className="flex flex-wrap gap-1.5">
-              {PRICE_OPTIONS.map((opt) => (
+              {sceneConfig.priceOptions.map((opt) => (
                 <button
                   key={opt.value}
                   type="button"