Add authenticated global economic calendar with Jin10 fallback

Collect macroeconomic releases, events and holidays through the official browser SDK with resumable history from 2025. Preserve evidence, revisions and observation times, and merge verified series with official fields taking priority.

Add category filters, field provenance, coverage and connection status. Verify calendar persistence and deployment recovery in isolated acceptance checks.

web/src/pages/calendar/presentation.ts

@@ -0,0 +1,20 @@
+import type { CalendarItem } from "@@/apis/calendar/type"
+import dayjs from "dayjs"
+import timezone from "dayjs/plugin/timezone"
+import utc from "dayjs/plugin/utc"
+
+dayjs.extend(utc)
+dayjs.extend(timezone)
+export const zone = "Asia/Shanghai"
+export const sources: Record<string, string> = { bls: "BLS", bea: "BEA", fed: "美联储", umich: "密歇根大学", ecb: "欧洲央行", eurostat: "Eurostat", boe: "英国央行", ons: "ONS", destatis: "Destatis", insee: "INSEE", dol: "美国劳工部 DOL", eia: "美国能源信息署 EIA", adp: "ADP", jin10: "金十" }
+export function flagUrl(item: CalendarItem) {
+  if (["US", "EA", "GB", "DE", "FR"].includes(item.country_code)) return `/flags/${item.country_code.toLowerCase()}.svg`
+  return /^[A-Z]{2}$/.test(item.country_code) ? `https://cdn.jin10.com/assets/img/commons/flag/${encodeURIComponent(item.country_name)}.png` : null
+}
+export function timeLabel(item: CalendarItem) {
+  return item.time_precision === "day" ? "全天" : item.time_precision === "tentative" ? "待定" : dayjs(item.scheduled_at).tz(zone).format("HH:mm")
+}
+export const value = (v: string | null, unit: string | null) => v === null ? "—" : `${v}${unit ?? ""}`
+export function forecastNote(item: Pick<CalendarItem, "forecast_observed_at" | "scheduled_at">) {
+  return item.forecast_observed_at && Date.parse(item.forecast_observed_at) >= Date.parse(item.scheduled_at) ? "发布后补取" : "时点未核实"
+}