feat(schema): add note.description and note.consolidated_at

Spec: docs/superpowers/specs/2026-05-13-task-as-durable-record-design.md

- description: user-stated goal / initial context for tasks (NULL for
  knowledge notes).
- consolidated_at: timestamp of the most recent auto-summary pass (NULL
  until first consolidation).
- Migration 0044 backfills description from body for existing rows where
  status IS NOT NULL (i.e. tasks). Body left in place; first consolidation
  pass will overwrite it.

alembic/versions/0044_add_note_description_and_consolidated_at.py

@@ -0,0 +1,48 @@
+"""add note.description and note.consolidated_at
+
+Revision ID: 0044
+Revises: 0043
+Create Date: 2026-05-13
+
+Adds two columns to the ``notes`` table to support the task-as-durable-record
+design (spec 2026-05-13):
+
+- ``description``: user-stated goal / initial context. Meaningful when
+  ``is_task=true``; left NULL on knowledge notes.
+- ``consolidated_at``: timestamp of the most recent auto-summary pass. NULL
+  until the first consolidation runs.
+
+Backfill: for existing tasks we copy ``body`` into ``description`` so the
+user's original goal text is preserved when ``body`` is later overwritten by
+the auto-summary pipeline. The brief duplication window between
+``body`` and ``description`` is harmless and resolves on the first
+consolidation pass.
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "0044"
+down_revision = "0043"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("notes", sa.Column("description", sa.Text(), nullable=True))
+    op.add_column(
+        "notes",
+        sa.Column("consolidated_at", sa.DateTime(timezone=True), nullable=True),
+    )
+    # is_task is a Python property (status IS NOT NULL); there's no DB column
+    # of that name. Backfill description from body for everything that
+    # qualifies as a task at the model layer.
+    op.execute(
+        "UPDATE notes SET description = body "
+        "WHERE status IS NOT NULL AND body IS NOT NULL"
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("notes", "consolidated_at")
+    op.drop_column("notes", "description")

src/fabledassistant/models/note.py

@@ -32,6 +32,10 @@ class Note(Base, TimestampMixin):
     )
     title: Mapped[str] = mapped_column(Text, default="")
     body: Mapped[str] = mapped_column(Text, default="")
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    consolidated_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
     tags: Mapped[list[str]] = mapped_column(ARRAY(Text), default=list)
     parent_id: Mapped[int | None] = mapped_column(
         Integer, ForeignKey("notes.id", ondelete="SET NULL"), nullable=True
@@ -81,6 +85,10 @@ class Note(Base, TimestampMixin):
             "id": self.id,
             "title": self.title,
             "body": self.body,
+            "description": self.description,
+            "consolidated_at": (
+                self.consolidated_at.isoformat() if self.consolidated_at else None
+            ),
             "tags": self.tags or [],
             "parent_id": self.parent_id,
             "project_id": self.project_id,