feat(F.14): Unified Task System — F-TASK-MODEL/API/AGENT/WORK/UI/MIG/GOAL/TEST

- F-TASK-MODEL: Extended Task model with polymorphic assignee/entity/creator, subtasks, dependencies, task_type, success_criteria, progress
- F-TASK-API: Extended task routes with polymorphic filters, subtasks, dependencies, new lifecycle
- F-TASK-AGENT: ai_tools.py (191 lines) — create_task, assign_task, update_task_status, decompose_goal tools
- F-TASK-WORK: workstream.py — task_card and goal_card blocks in communication system
- F-TASK-UI: TaskBoard.tsx, TaskDetail.tsx, GoalView.tsx frontend components
- F-TASK-MIG: Migration 0124 — new columns, data migration for contact_id/assigned_to
- F-TASK-GOAL: Progress aggregation, success criteria evaluation, parent status propagation
- F-TASK-TEST: test_unified_tasks.py (414 lines)
- i18n updates for task system

app/plugins/builtins/tasks/workstream.py

@@ -0,0 +1,106 @@
+"""Task → Workstream integration (F-TASK-WORK).
+
+Posts task_card and goal_card blocks to the communication system so tasks
+and goals appear in the workstream with live status and progress.
+"""
+
+from __future__ import annotations
+
+import logging
+import uuid
+from typing import Any
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.plugins.builtins.tasks.models import Task
+
+logger = logging.getLogger(__name__)
+
+
+def _task_card_data(task: Task) -> dict[str, Any]:
+    """Build a task_card block payload for a task."""
+    return {
+        "task_id": str(task.id),
+        "title": task.title,
+        "status": task.status,
+        "priority": task.priority,
+        "task_type": task.task_type,
+        "assignee_type": task.assignee_type,
+        "assignee_id": str(task.assignee_id) if task.assignee_id else None,
+        "entity_type": task.entity_type,
+        "entity_id": str(task.entity_id) if task.entity_id else None,
+        "parent_task_id": str(task.parent_task_id) if task.parent_task_id else None,
+        "due_date": task.due_date.isoformat() if task.due_date else None,
+        "progress": task.progress or 0,
+    }
+
+
+def _goal_card_data(task: Task) -> dict[str, Any]:
+    """Build a goal_card block payload for a goal/milestone."""
+    return {
+        "goal_id": str(task.id),
+        "title": task.title,
+        "status": task.status,
+        "task_type": task.task_type,
+        "progress": task.progress or 0,
+        "target_date": task.target_date.isoformat() if task.target_date else None,
+        "success_criteria": task.success_criteria,
+        "parent_task_id": str(task.parent_task_id) if task.parent_task_id else None,
+    }
+
+
+async def post_task_to_workstream(
+    db: AsyncSession,
+    tenant_id: uuid.UUID,
+    task: Task,
+    *,
+    actor_id: uuid.UUID | None = None,
+    actor_type: str = "user",
+    conversation_id: uuid.UUID | None = None,
+    content: str | None = None,
+) -> uuid.UUID | None:
+    """Post a task_card block to the workstream.
+
+    Returns the created message ID, or None if the communication system is
+    unavailable.
+    """
+    try:
+        from app.plugins.builtins.kommunikation.services import send_message
+
+        block_type = "goal_card" if task.task_type in ("goal", "milestone") else "task_card"
+        block_data = _goal_card_data(task) if block_type == "goal_card" else _task_card_data(task)
+        message_id = await send_message(
+            db=db,
+            tenant_id=tenant_id,
+            sender_id=actor_id or task.created_by or task.id,
+            sender_type=actor_type,
+            conversation_id=conversation_id,
+            content=content or f"{task.title} ({task.status})",
+            blocks=[{"type": block_type, "data": block_data}],
+            metadata={"source": "tasks", "task_id": str(task.id)},
+        )
+        return message_id
+    except Exception:
+        logger.exception("Failed to post task %s to workstream", task.id)
+        return None
+
+
+async def post_task_status_update(
+    db: AsyncSession,
+    tenant_id: uuid.UUID,
+    task: Task,
+    *,
+    old_status: str | None = None,
+    actor_id: uuid.UUID | None = None,
+    actor_type: str = "user",
+    conversation_id: uuid.UUID | None = None,
+) -> uuid.UUID | None:
+    """Post a status-change update to the workstream."""
+    content = f"Status geändert: {task.title} → {task.status}"
+    if old_status and old_status != task.status:
+        content = f"Status geändert: {task.title} ({old_status} → {task.status})"
+    return await post_task_to_workstream(
+        db, tenant_id, task,
+        actor_id=actor_id, actor_type=actor_type,
+        conversation_id=conversation_id, content=content,
+    )