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.test.ts

@@ -393,6 +393,14 @@ describe("translation resources", () => {
     expect(en.message.question.otherPlaceholder).toBe("Other...");
     expect(en.message.todo.title).toBe("Tasks");
     expect(en.message.todo.empty).toBe("No tasks yet.");
+    expect(en.message.todo.tasksProgressCurrent).toBe("{{completed}}/{{total}} tasks · {{task}}");
+    expect(en.message.todo.activity).toEqual({
+      created: "Created {{count}} tasks",
+      added: "Added",
+      started: "Started",
+      completed: "Completed",
+      reopened: "Reopened",
+    });
   });
 
   it("includes workspace tab toast keys for the Batch 4J migration", () => {