feat: personal/work area toggle

Global lens in the home header: every list, Today, Projects and Review
show only the active area; new rows are born into it. Tasks and projects
gain an area column (personal default); the task form's Area chip
re-files across areas.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SW5iVXkZ2JBHgyweMCRymY

app/src/lib/store.test.ts

@@ -21,6 +21,7 @@ const store = await import("./store");
 beforeEach(async () => {
   storage.clear();
   await store.hydrate();
+  store.setArea("personal");
 });
 
 const find = (id: string) => store.getState().tasks.find((t) => t.id === id)!;
@@ -61,3 +62,66 @@ describe("completeTask", () => {
     expect(store.completeTask("nope")).toBeNull();
   });
 });
+
+describe("area lens", () => {
+  test("new rows are born into the active area and selectors filter by it", () => {
+    const home = store.createTask({ title: "home" });
+    store.setArea("work");
+    const office = store.createTask({ title: "office" });
+    const proj = store.createProject({ name: "Q4" });
+    expect(home.area).toBe("personal");
+    expect(office.area).toBe("work");
+    expect(proj.area).toBe("work");
+
+    // The store is module state shared across tests, so assert on membership
+    // and on every visible row's area rather than on exact lists.
+    const ids = (s: ReturnType<typeof store.getState>) => store.tasksByStatus(s, "next").map((t) => t.id);
+    let s = store.getState();
+    expect(ids(s)).toContain(office.id);
+    expect(ids(s)).not.toContain(home.id);
+    expect(store.tasksByStatus(s, "next").every((t) => t.area === "work")).toBe(true);
+    expect(store.activeProjects(s).map((p) => p.id)).toEqual([proj.id]);
+
+    store.setArea("personal");
+    s = store.getState();
+    expect(ids(s)).toContain(home.id);
+    expect(ids(s)).not.toContain(office.id);
+    expect(store.activeProjects(s).some((p) => p.id === proj.id)).toBe(false);
+  });
+
+  test("area persists across hydrate", async () => {
+    store.setArea("work");
+    expect(storage.get("area_v1")).toBe("work");
+  });
+
+  test("rows cached without an area count as personal", () => {
+    // Simulate a pre-migration cache row.
+    const legacy = store.createTask({ title: "old" });
+    delete (legacy as { area?: string }).area;
+    store.setArea("work");
+    expect(store.todayTasks(store.getState()).overdue).toEqual([]);
+    store.setArea("personal");
+    expect(store.tasksByStatus(store.getState(), "next").some((t) => t.id === legacy.id)).toBe(true);
+  });
+
+  test("today, review and contexts respect the lens", () => {
+    store.createTask({ title: "p", due_date: "2000-01-01", context: "@home" });
+    store.setArea("work");
+    store.createTask({ title: "w", due_date: "2000-01-01", context: "@office" });
+    const s = store.getState();
+    expect(store.todayTasks(s).overdue.every((t) => t.area === "work")).toBe(true);
+    expect(store.todayTasks(s).overdue.map((t) => t.title)).toContain("w");
+    expect(store.reviewBuckets(s).overdue.map((t) => t.title)).toContain("w");
+    expect(store.reviewBuckets(s).overdue.map((t) => t.title)).not.toContain("p");
+    expect(store.knownContexts(s)).toEqual(["@office"]);
+  });
+
+  test("completing a repeating work task spawns into work", () => {
+    store.setArea("work");
+    const t = store.createTask({ title: "standup", repeat: "daily", due_date: "2000-01-01" });
+    store.setArea("personal");
+    store.completeTask(t.id);
+    const spawned = store.getState().tasks.find((x) => x.title === "standup" && x.status === "next")!;
+    expect(spawned.area).toBe("work");
+  });
+});