feat(api): track previous in_progress_at during task status transitions

backend/app/api/tasks.py

@@ -2137,8 +2137,10 @@ async def _apply_non_lead_agent_task_rules(
                 raise _blocked_task_error(blocked_ids)
         if status_value == "inbox":
             update.task.assigned_agent_id = None
+            update.task.previous_in_progress_at = update.task.in_progress_at
             update.task.in_progress_at = None
         elif status_value == "review":
+            update.task.previous_in_progress_at = update.task.in_progress_at
             update.task.assigned_agent_id = None
             update.task.in_progress_at = None
         else:
@@ -2199,8 +2201,12 @@ async def _apply_admin_task_rules(
     if "status" in update.updates:
         status_value = _required_status_value(update.updates["status"])
         if status_value == "inbox":
+            update.task.previous_in_progress_at = update.task.in_progress_at
             update.task.assigned_agent_id = None
             update.task.in_progress_at = None
+        elif status_value == "review":
+            update.task.previous_in_progress_at = update.task.in_progress_at
+            update.task.in_progress_at = None
         elif status_value == "in_progress":
             update.task.in_progress_at = utcnow()
 
@@ -2353,8 +2359,8 @@ async def _finalize_updated_task(
         comment_text = (update.comment or "").strip()
         review_comment_author = update.task.assigned_agent_id or update.previous_assigned
         review_comment_since = (
-            update.task.in_progress_at
-            if update.task.in_progress_at is not None
+            update.task.previous_in_progress_at
+            if update.task.previous_in_progress_at is not None
             else update.previous_in_progress_at
         )
         if not comment_text and not await has_valid_recent_comment(

backend/app/models/tasks.py

@@ -27,6 +27,7 @@ class Task(TenantScoped, table=True):
     priority: str = Field(default="medium", index=True)
     due_at: datetime | None = None
     in_progress_at: datetime | None = None
+    previous_in_progress_at: datetime | None = None
 
     created_by_user_id: UUID | None = Field(
         default=None,

backend/migrations/versions/a2f6c9d4b7e8_add_previous_in_progress_at_to_tasks.py

@@ -0,0 +1,31 @@
+"""Track prior in_progress_at during status transitions.
+
+Revision ID: a2f6c9d4b7e8
+Revises: 4c1f5e2a7b9d
+Create Date: 2026-02-15 00:00:00.000000
+"""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+
+
+# revision identifiers, used by Alembic.
+revision = "a2f6c9d4b7e8"
+down_revision = "4c1f5e2a7b9d"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    """Add previous_in_progress_at column to tasks."""
+    op.add_column(
+        "tasks",
+        sa.Column("previous_in_progress_at", sa.DateTime(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    """Drop previous_in_progress_at column from tasks."""
+    op.drop_column("tasks", "previous_in_progress_at")

backend/tests/test_task_agent_permissions.py

@@ -340,6 +340,7 @@ async def test_non_lead_agent_moves_task_to_review_and_task_unassigns() -> None:
             gateway_id = uuid4()
             worker_id = uuid4()
             task_id = uuid4()
+            in_progress_at = utcnow()
 
             session.add(Organization(id=org_id, name="org"))
             session.add(
@@ -377,7 +378,7 @@ async def test_non_lead_agent_moves_task_to_review_and_task_unassigns() -> None:
                     description="",
                     status="in_progress",
                     assigned_agent_id=worker_id,
-                    in_progress_at=utcnow(),
+                    in_progress_at=in_progress_at,
                 ),
             )
             await session.commit()
@@ -397,6 +398,12 @@ async def test_non_lead_agent_moves_task_to_review_and_task_unassigns() -> None:
             assert updated.status == "review"
             assert updated.assigned_agent_id is None
             assert updated.in_progress_at is None
+
+            refreshed_task = (
+                (await session.exec(select(Task).where(col(Task.id) == task_id))).first()
+            )
+            assert refreshed_task is not None
+            assert refreshed_task.previous_in_progress_at == in_progress_at
     finally:
         await engine.dispose()