Show live task progress while agents work (#3227)

* feat(agents): surface live task progress

Keep current task state above the composer and turn task snapshots into semantic timeline activity. Normalize provider task protocols while preserving genuine plan flows.

* fix(agents): admit tasks through stream sequencing

* test(agents): expect normalized task status

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

@@ -336,6 +336,15 @@ export const ja: TranslationResources = {
     todo: {
       title: "タスク",
       empty: "タスクがまだありません。",
+      tasksProgress: "{{completed}}/{{total}}タスク",
+      tasksProgressCurrent: "{{completed}}/{{total}}タスク · {{task}}",
+      activity: {
+        created: "{{count}}件のタスクを作成",
+        added: "追加",
+        started: "開始",
+        completed: "完了",
+        reopened: "再開",
+      },
     },
     compaction: {
       loading: "コンテキストを圧縮中...",