feat(traffic-flow): enhance country handling in flow analytics

- Introduced country-specific handling in traffic flow analytics, including new mappings for country nodes and edges.
- Added mock data for countries and their respective service paths to improve visualization in the Network Map.
- Updated the `countryName` function to utilize `Intl.DisplayNames` for better localization of country names.
- Enhanced tests to validate country handling and ensure accurate representation in flow analytics.

Co-authored-by: Cursor <[email protected]>

components/flag.tsx

@@ -20,9 +20,29 @@ const COUNTRY_NAMES: Record<string, string> = {
   HK: "Гонконг",
 }
 
-/** Country name in Russian (fallback to code) */
+let regionNames: Intl.DisplayNames | null | undefined
+
+function regionDisplayName(iso: string): string | undefined {
+  try {
+    if (regionNames === undefined) {
+      regionNames = typeof Intl !== "undefined" && "DisplayNames" in Intl
+        ? new Intl.DisplayNames(["ru"], { type: "region" })
+        : null
+    }
+    return regionNames?.of(iso) ?? undefined
+  } catch {
+    return undefined
+  }
+}
+
+/** Country name in Russian (fallback to ISO code) */
 export function countryName(code: string): string {
-  return COUNTRY_NAMES[code.toUpperCase()] ?? code
+  const iso = code.toUpperCase()
+  if (!iso) return code
+  if (COUNTRY_NAMES[iso]) return COUNTRY_NAMES[iso]
+  const intl = regionDisplayName(iso)
+  if (intl && intl !== iso) return intl
+  return iso
 }
 
 interface FlagProps {
@@ -39,6 +59,13 @@ function nearestCdnSize(px: number): number {
   return CDN_SIZES.find(s => s >= px) ?? CDN_SIZES[CDN_SIZES.length - 1]
 }
 
+/** CDN URL for SVG `<image href>` (flagcdn widths only). */
+export function flagCdnUrl(code: string, size = 40): string | null {
+  const lower = code.toLowerCase()
+  if (!/^[a-z]{2}$/.test(lower)) return null
+  return `https://flagcdn.com/w${nearestCdnSize(size)}/${lower}.png`
+}
+
 /**
  * Renders a flag <img> for a given ISO 3166-1 alpha-2 country code.
  * Source: https://flagcdn.com — free CDN, no API key needed.

components/network-map/country-flag-svg.tsx

@@ -0,0 +1,17 @@
+"use client"
+
+import { flagCdnUrl } from "@/components/flag"
+
+export function CountryFlagSvg({ iso, size = 22 }: { iso: string; size?: number }) {
+  const url = flagCdnUrl(iso, size)
+  if (!url) return null
+  const h = Math.round(size * 0.75)
+  return (
+    <image
+      href={url}
+      width={size}
+      height={h}
+      preserveAspectRatio="xMidYMid meet"
+    />
+  )
+}