refactor/match_collector: refactor platform handling logic

match_collector/champion_stat.ts

@@ -11,6 +11,7 @@ import {
   areTreeSimilars,
   treeDeriveTags
 } from './item_tree'
+import { PLATFORM_KEYS } from './platform'
 
 import { Match, Timeline, Participant, Frame } from './api'
 
@@ -345,10 +346,10 @@ function handleMatch(match: Match, champions: Map<number, ChampionData>, platfor
     // Track region distribution for this lane
     if (lane.regionDistribution && platform) {
       const platformKey = platform.toLowerCase()
-      if (platformKey === 'euw1') lane.regionDistribution.euw++
-      else if (platformKey === 'eun1') lane.regionDistribution.eun++
-      else if (platformKey === 'na1') lane.regionDistribution.na++
-      else if (platformKey === 'kr') lane.regionDistribution.kr++
+      const regionKey = PLATFORM_KEYS[platformKey]
+      if (regionKey) {
+        lane.regionDistribution[regionKey]!++
+      }
     }
 
     // Initialize matchups if not present