feat(views): anonymous daily view counter with social-proof badge

- New table symbol_views_daily(code, view_date, views) via migration 004.
- POST /api/views/{code} UPSERTs and returns today_views; GET returns
  today + last_7d + trend (last 7 days).
- Client dedupes via localStorage (views:logged map keyed by KST date) so a
  given browser counts once per day per code; refresh/extra tabs don't inflate.
- PriceHero shows "오늘 N명이 봤어요" pill when viewsToday > 0.

Read-only social proof — Toss 의 종목 상세에서 익명 카운트로 진입 신호를 주는 패턴.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/lib/api.ts

@@ -352,4 +352,28 @@ export const api = {
     getJson<OrderbookResponse>(`/api/orderbook/${encodeURIComponent(code)}`),
   fundamentals: (code: string) =>
     getJson<FundamentalsResponse>(`/api/fundamentals/${encodeURIComponent(code)}`),
+  recordView: (code: string) =>
+    getJson<RecordViewResponse>(`/api/views/${encodeURIComponent(code)}`, {
+      method: "POST",
+    }),
+  views: (code: string) =>
+    getJson<ViewsResponse>(`/api/views/${encodeURIComponent(code)}`),
+};
+
+export type RecordViewResponse = {
+  ok: boolean;
+  code?: string;
+  today_views: number;
+};
+
+export type ViewsTrendPoint = {
+  date: string;
+  views: number;
+};
+
+export type ViewsResponse = {
+  code: string;
+  today_views: number;
+  last_7d_views: number;
+  trend: ViewsTrendPoint[];
 };