feat(R07): task repository, schedule calculator, Qt clock adapter, task/AI-planner services

Team Hoa, EPIC R07 (Scheduling & Workflow Runtime) - Team Hoa scope only
(R07-T01 -> T05; R07-T06 Co4EWorkflowService is Team Nam's).

- R07-T01: infrastructure/persistence/json/task_repository_impl.py wraps
  core/tasks.py's CRUD; core/tasks.py::save_task now writes through
  atomic_write.write_json (same durability fix as R06-T02, save_task was
  still doing a plain write_text).
- R07-T02: domain/tasks/schedule_calculator.py::ScheduleCalculator - the
  cron/interval/daily/weekly/monthly due-time math extracted from
  core/tasks.py, pure Python with is_holiday/make_cron injected so domain/
  never imports core (ADR-001 I2). core/tasks.py keeps its old function
  names as thin wrappers so every existing caller is unchanged. This was
  previously untested; now has its own unit suite.
- R07-T03: infrastructure/qt/qt_scheduler_clock.py::QtSchedulerClock wraps
  the QTimer TaskScheduler used to own directly, injected via a new
  `clock=` constructor param (defaults to a real one). Originally planned
  at platform/qt/... ; moved after confirming that name shadows the
  stdlib platform module (used by core/windows_sandbox_vm.py,
  core/appcontainer_sandbox.py) whenever the repo root is on sys.path.
  tests/fakes/fake_clock.py lets scheduler dispatch be tested tick-by-tick
  with no Qt event loop.
- R07-T04: application/scheduling/task_application_service.py centralizes
  run_now/duplicate/pause/delete/bulk_delete and the Kanban drag-drop
  business rules (move_to_status), currently only reachable by driving
  the real ui/schedule_task_tab.py widget.
- R07-T05: application/scheduling/ai_task_planner_service.py wraps
  core/ai_task_planner.py::plan_tasks and core/task_import.py::import_tasks
  as a seam, plus the attachment-stamping step that used to only exist
  inside the AI-create dialog's worker closure.

pytest: 328 pass (same 4 pre-existing failures as the R05/R06 baseline,
unrelated to this work - see docs/refactor/BaoCao_TeamHoa_R05_R06.md).
scripts/check_imports.py: PASS.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

application/scheduling/__init__.py

@@ -0,0 +1,6 @@
+"""Application services for Schedule Task (EPIC R07)."""
+
+from .ai_task_planner_service import AiTaskPlannerService
+from .task_application_service import MoveResult, RunNowResult, TaskApplicationService
+
+__all__ = ["TaskApplicationService", "RunNowResult", "MoveResult", "AiTaskPlannerService"]

application/scheduling/ai_task_planner_service.py

@@ -0,0 +1,94 @@
+"""AiTaskPlannerService - AI-generate / import task lists, outside the widget
+(R07-T05).
+
+``ui/schedule_task_tab.py``'s ``_AiCreateDialog`` already delegates the
+actual planning to two existing pure functions —
+``core/ai_task_planner.py::plan_tasks`` (natural-language description ->
+task dicts, via the active provider) and
+``core/task_import.py::import_tasks`` (Excel/CSV/JSON -> task dicts) — so
+this service does not reimplement either. What it DOES own is one small
+piece of business logic that currently only exists inside the dialog's
+``AgentWorker`` job closure (``_generate``'s ``job()``): every AI-generated
+task must carry the SAME file/link attachments the user attached to the
+request, so they're available again at run time, not just visible to the
+planner while it drafts the task list. Leaving that step trapped in a Qt
+worker closure means it can only be exercised by driving the real dialog;
+here it's a plain, independently testable method.
+
+Pure Python: no Qt import. The provider is a constructor-injected factory
+(``() -> Provider``, no arguments — matches ``AppContext.build_active_
+provider``), the same dependency-inversion shape
+``application/conversations/conversation_application_service.py`` (R04-T03)
+uses for ITS provider factory.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any, Callable, Dict, List, Optional, Sequence, Union
+
+ProviderFactory = Callable[[], Any]
+CancelFn = Callable[[], bool]
+
+
+class AiTaskPlannerService:
+    """AI task generation + file/Excel/CSV/JSON import, for
+    ``presentation/scheduling/ai_task_creator_dialog.py`` and
+    ``ai_task_import_dialog.py`` (R08-T11) to call instead of importing
+    ``core.ai_task_planner``/``core.task_import`` directly.
+
+    Args:
+        provider_factory: ``() -> Provider``. Production passes
+            ``AppContext.build_active_provider``; tests pass a lambda
+            returning a :class:`FakeProvider`.
+    """
+
+    def __init__(self, provider_factory: Optional[ProviderFactory] = None) -> None:
+        self._provider_factory = provider_factory
+
+    def plan(
+        self,
+        description: str,
+        *,
+        file_paths: Sequence[str] = (),
+        links: Sequence[str] = (),
+        provider: Any = None,
+        cancel: Optional[CancelFn] = None,
+    ) -> List[Dict[str, Any]]:
+        """Turn ``description`` into a list of NOT-yet-saved task dicts.
+
+        ``provider`` overrides the constructor's factory for this one call
+        (useful for tests, or a caller that already resolved a provider);
+        omit it to use the injected factory. Raises ``RuntimeError`` when
+        no provider is available at all, or when the model's reply had no
+        parseable task list (same error ``core.ai_task_planner.plan_tasks``
+        already raises).
+        """
+        resolved = provider if provider is not None else self._resolve_provider()
+        from cowork_local.core.ai_task_planner import plan_tasks
+
+        planned = plan_tasks(resolved, description, cancel=cancel)
+        # Attachments apply to EVERY generated task so they're still there
+        # when the task actually runs, not just while the planner drafts it
+        # (see module docstring — this used to only happen inside the
+        # dialog's worker closure).
+        for task in planned:
+            task["input"]["file_paths"] = list(file_paths)
+            task["input"]["links"] = list(links)
+        return planned
+
+    def import_file(self, path: Union[str, Path]) -> List[Dict[str, Any]]:
+        """Excel/CSV/JSON -> NOT-yet-saved task dicts, auto-chained in file
+        order. Raises ``ValueError`` with a human-readable message on an
+        unusable/unsupported file (same contract
+        ``core.task_import.import_tasks`` already has)."""
+        from cowork_local.core.task_import import import_tasks
+
+        return import_tasks(path)
+
+    def _resolve_provider(self) -> Any:
+        if self._provider_factory is None:
+            raise RuntimeError("No provider available to plan tasks.")
+        return self._provider_factory()
+
+
+__all__ = ["AiTaskPlannerService"]

application/scheduling/task_application_service.py

@@ -0,0 +1,172 @@
+"""TaskApplicationService - task CRUD + dispatch, outside the widget (R07-T04).
+
+``ui/schedule_task_tab.py`` currently does all of this by importing
+``core/tasks.py`` module functions directly and calling
+``self.scheduler.run_now(...)`` inline inside Qt slot methods
+(``_run_now``, ``_context_menu``'s duplicate/pause/delete branches,
+``_on_task_dropped``'s per-lane business rules). None of it is Qt — it's
+plain CRUD plus a few small rules ("a manual task never auto-runs",
+"dropping a card on Done disables its schedule so it won't re-fire",
+"dropping on Scheduled with no time set needs the editor, not a silent
+no-op") — but it can only be exercised today by driving the real widget.
+
+This service is the seam ``presentation/scheduling/kanban_board_widget.py``
+(R08-T11) calls instead: same rules, same
+:class:`~infrastructure.persistence.json.task_repository_impl.TaskRepository`
+underneath, testable with no Qt at all.
+
+Pure Python: no Qt import. ``run_now`` dispatch is a plain injected callable
+(production wires ``TaskScheduler.run_now``; tests inject a stub), the same
+constructor-injection shape ``application/conversations/conversation_
+application_service.py`` (R04-T03) uses for its provider factory.
+"""
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any, Callable, Dict, List, Optional
+
+# "TaskRepository" here is a Protocol-shaped name, not an import: this module
+# only calls .get/.save/.delete/.duplicate, so any object with that shape
+# (the real infrastructure.persistence.json.task_repository_impl.TaskRepository,
+# or a test double) works without this file importing infrastructure/ at
+# module scope.
+RunNowFn = Callable[[str], bool]
+
+
+@dataclass
+class RunNowResult:
+    """Outcome of asking a task to run immediately.
+
+    ``reason`` is one of ``""`` (ok), ``"not_found"``, ``"manual_task"``
+    (manual tasks never auto-run — spec: they exist to be run by a human),
+    ``"no_scheduler"`` (no ``run_now`` callable was wired in), or
+    ``"already_running"`` (the scheduler's own dedupe rejected it).
+    """
+
+    ok: bool
+    reason: str = ""
+
+
+@dataclass
+class MoveResult:
+    """Outcome of dropping a task card onto a Kanban lane
+    (``move_to_status``). The caller (kanban widget) uses the flags to decide
+    what to show — a full re-render, a "task is running" toast, or opening
+    the task editor — without re-deriving the business rule itself."""
+
+    task: Optional[Dict[str, Any]]
+    blocked: bool = False          # dropped while already running — ignored
+    ran_now: bool = False          # dropped on the Running lane — dispatched
+    run_now_result: Optional[RunNowResult] = None
+    needs_schedule: bool = False   # dropped on Scheduled with no run_at set — needs editing
+
+
+class TaskApplicationService:
+    """CRUD + dispatch for Schedule Task, backed by a ``TaskRepository``.
+
+    Args:
+        repository: a ``TaskRepository``-shaped object (``.get``, ``.save``,
+            ``.delete``, ``.duplicate``). Production passes
+            ``infrastructure.persistence.json.task_repository_impl.
+            TaskRepository()``; tests pass one scoped to a ``tmp_path``.
+        run_now: ``(task_id) -> bool``. Production passes
+            ``TaskScheduler.run_now``; ``None`` means no scheduler is wired
+            (matches the widget's own "no scheduler" guard today).
+    """
+
+    def __init__(self, repository: Any, run_now: Optional[RunNowFn] = None) -> None:
+        self._repository = repository
+        self._run_now = run_now
+
+    # -- single-task actions ------------------------------------------------ #
+    def run_now(self, task_id: str) -> RunNowResult:
+        """Dispatch ``task_id`` immediately. A "Run now" always counts as
+        manual approval (spec §13) — this is the ONE path that bypasses
+        ``execution.requires_approval``, same as the scheduler's own
+        ``run_now`` already does."""
+        task = self._repository.get(task_id)
+        if task is None:
+            return RunNowResult(False, "not_found")
+        if task.get("task_type") == "manual":
+            return RunNowResult(False, "manual_task")
+        if self._run_now is None:
+            return RunNowResult(False, "no_scheduler")
+        ok = self._run_now(task_id)
+        return RunNowResult(ok, "" if ok else "already_running")
+
+    def duplicate(self, task_id: str) -> Optional[Dict[str, Any]]:
+        """A saved copy with a fresh identity — see
+        ``core/tasks.py::duplicate_task`` for what's preserved/reset."""
+        task = self._repository.get(task_id)
+        if task is None:
+            return None
+        dup = self._repository.duplicate(task)
+        self._repository.save(dup)
+        return dup
+
+    def toggle_pause(self, task_id: str) -> Optional[Dict[str, Any]]:
+        """Pause a task, or resume a paused one back to Backlog (matches
+        ``ui/schedule_task_tab.py``'s context-menu action exactly — resuming
+        does NOT restore whatever status the task had before pausing, only
+        Backlog, so the user re-schedules explicitly rather than a stale
+        schedule silently re-firing)."""
+        task = self._repository.get(task_id)
+        if task is None:
+            return None
+        task["status"] = "backlog" if task.get("status") == "paused" else "paused"
+        self._repository.save(task)
+        return task
+
+    def delete(self, task_id: str) -> bool:
+        if self._repository.get(task_id) is None:
+            return False
+        self._repository.delete(task_id)
+        return True
+
+    def bulk_delete(self, task_ids: List[str]) -> int:
+        """Delete every id in ``task_ids``; returns how many actually
+        existed (mirrors ``_confirm_and_delete_selected``'s best-effort
+        loop — a stale id in the selection doesn't abort the rest)."""
+        return sum(1 for tid in task_ids if self.delete(tid))
+
+    # -- Kanban drag/drop ----------------------------------------------------- #
+    def move_to_status(self, task_id: str, new_status: str) -> Optional[MoveResult]:
+        """Apply the business rule behind dropping a card into a lane
+        (``ui/schedule_task_tab.py::_on_task_dropped``, moved here so it's
+        testable without a real ``QListWidget`` drag gesture):
+
+        * already running -> the drop is ignored (a running task can't be
+          re-filed by dragging it).
+        * dropped on Running -> runs it now (counts as manual approval).
+        * dropped on Done -> marks it done AND disables its schedule, so a
+          repeating task marked done by hand doesn't quietly re-fire later.
+        * dropped on Scheduled with no ``run_at`` set yet -> saved as-is but
+          flagged ``needs_schedule`` — the caller should open the editor
+          rather than leave a Scheduled card that will never actually run.
+        * anything else -> plain status change.
+        """
+        task = self._repository.get(task_id)
+        if task is None:
+            return None
+        if task.get("status") == "running":
+            return MoveResult(task=task, blocked=True)
+        if new_status == "running":
+            result = self.run_now(task_id)
+            return MoveResult(task=self._repository.get(task_id), ran_now=True, run_now_result=result)
+        if new_status == "done":
+            task["status"] = "done"
+            task["schedule"]["enabled"] = False
+            self._repository.save(task)
+            return MoveResult(task=task)
+        task["status"] = new_status
+        if new_status == "scheduled" and not task["schedule"].get("enabled"):
+            if task["schedule"].get("run_at"):
+                task["schedule"]["enabled"] = True
+            else:
+                self._repository.save(task)
+                return MoveResult(task=task, needs_schedule=True)
+        self._repository.save(task)
+        return MoveResult(task=task)
+
+
+__all__ = ["TaskApplicationService", "RunNowResult", "MoveResult"]