Feature/delta team/epic r04 (#7)

## Summary

epic r04 - begin refactor

## Change Type

- [x] Cowork feature
- [ ] Bug fix
- [ ] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

---------

Co-authored-by: Anh Tran Nguyen Minh <anhtnm1@fpt.com>
Co-authored-by: Huong Le Thi Thien <huongltt35@fpt.com>
Co-authored-by: Nam Pham Dinh Thanh <nampdt@fpt.com>
Co-authored-by: Vu Dam Tuan <vudt15@fpt.com>
Co-authored-by: Hiep Ha Van <hiephv3@fpt.com>
Co-authored-by: Lam Hoang Van <lamhv7@fpt.com>
Reviewed-on: #7
Co-authored-by: Duy Le Huu <duylh19@fpt.com>

infrastructure/persistence/json/task_repository_impl.py

@@ -0,0 +1,95 @@
+"""TaskRepository - an object-shaped, atomic-write-backed facade over
+``core/tasks.py`` (R07-T01).
+
+``core/tasks.py``'s module-level functions (``list_tasks``, ``load_task``,
+``save_task``, ``delete_task``, ``new_task``, ``duplicate_task``) are still
+what every existing call site (``core/task_scheduler.py``,
+``core/task_executors.py``, ``ui/schedule_task_tab.py``) uses, and stay that
+way - ``save_task`` now writes through :func:`atomic_write.write_json`
+itself (R07-T01, same class of durability fix already applied to
+``core/projects.py``/``core/history.py`` at R06-T02), so the fix applies
+whether or not a caller ever touches this class.
+
+This repository exists for the application layer
+(``application/scheduling``, R07-T04) to depend on an interface instead of
+reaching into ``core/`` directly. It is a thin pass-through today, not a
+re-implementation: same on-disk format, same directory, same functions
+underneath.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+
+class TaskRepository:
+    """CRUD over task dicts (see ``core/tasks.py::DEFAULT_TASK`` for shape),
+    scoped to one ``directory`` (defaults to the app's real ``TASKS_DIR``;
+    tests pass a ``tmp_path`` so nothing touches the user's real config
+    folder)."""
+
+    def __init__(self, directory: Optional[Path] = None) -> None:
+        """``directory`` để None thì dùng thư mục task mặc định.
+
+        Hai đường import cho cùng một hằng số: gói có thể được nạp dưới tên đầy đủ
+        ``cowork_local`` hoặc dưới dạng tương đối tuỳ cách chạy.
+        """
+        if directory is None:
+            try:
+                from cowork_local.core.tasks import TASKS_DIR
+            except ImportError:
+                from ...core.tasks import TASKS_DIR
+            self._directory = TASKS_DIR
+        else:
+            self._directory = directory
+
+    def list(self) -> List[Dict[str, Any]]:
+        """Liệt kê mọi task trong thư mục."""
+        try:
+            from cowork_local.core.tasks import list_tasks
+        except ImportError:
+            from ...core.tasks import list_tasks
+        return list_tasks(self._directory)
+
+    def get(self, task_id: str) -> Optional[Dict[str, Any]]:
+        """Đọc một task theo id; trả về ``None`` nếu không có."""
+        try:
+            from cowork_local.core.tasks import load_task
+        except ImportError:
+            from ...core.tasks import load_task
+        return load_task(task_id, self._directory)
+
+    def save(self, task: Dict[str, Any]) -> Path:
+        """Ghi task xuống đĩa (ghi nguyên tử) và trả về đường dẫn file."""
+        try:
+            from cowork_local.core.tasks import save_task
+        except ImportError:
+            from ...core.tasks import save_task
+        return save_task(task, self._directory)
+
+    def create(self, title: str = "", **overrides: Any) -> Dict[str, Any]:
+        """Tạo một task mới trong bộ nhớ theo mẫu mặc định; chưa ghi đĩa."""
+        try:
+            from cowork_local.core.tasks import new_task
+        except ImportError:
+            from ...core.tasks import new_task
+        return new_task(title, **overrides)
+
+    def duplicate(self, task: Dict[str, Any]) -> Dict[str, Any]:
+        """Nhân bản một task (id mới, trạng thái và lịch sử chạy được đặt lại)."""
+        try:
+            from cowork_local.core.tasks import duplicate_task
+        except ImportError:
+            from ...core.tasks import duplicate_task
+        return duplicate_task(task)
+
+    def delete(self, task_id: str) -> None:
+        """Xoá hẳn một task khỏi đĩa."""
+        try:
+            from cowork_local.core.tasks import delete_task
+        except ImportError:
+            from ...core.tasks import delete_task
+        delete_task(task_id, self._directory)
+
+
+__all__ = ["TaskRepository"]