feat(app): give composer track pills a segment per state

A mixed fan-out used to collapse the pill to its single most urgent
state, so a red dot beside "1 failed" over a child that was still
working read as the whole fan-out having stopped. Every state present
now gets its own mark and count, in the sidebar's status-group order.

packages/app/src/i18n/resources/ja.ts

@@ -1681,7 +1681,7 @@ export const ja: TranslationResources = {
     title: "サブエージェント",
     pillLabelOne: "サブエージェント 1 件",
     pillLabelMany: "サブエージェント {{count}} 件",
-    pillLabelRunning: "{{count}} 件実行中",
+    pillLabelWorking: "{{count}} 件実行中",
     pillLabelFailed: "{{count}} 件失敗",
     pillLabelNeedsInputOne: "1 件が入力待ち",
     pillLabelNeedsInputMany: "{{count}} 件が入力待ち",