fc5: migration 0015 + MigrationRun model (kind/status as String(32), API-validated)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

alembic/versions/0015_fc5_migration_run.py

@@ -0,0 +1,51 @@
+"""fc5: migration_run table
+
+Revision ID: 0015
+Revises: 0014
+Create Date: 2026-05-22
+
+Additive only. New table tracks each invocation of the FC-5 migration
+tooling (backup, gs, ir, ml_queue, verify, rollback). kind/status are
+plain String(32) — values validated at the API layer per the spec, not
+a Postgres ENUM (so adding kinds later doesn't need a schema migration).
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+revision: str = "0015"
+down_revision: Union[str, None] = "0014"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "migration_run",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("kind", sa.String(32), nullable=False, index=True),
+        sa.Column("status", sa.String(32), nullable=False, index=True),
+        sa.Column(
+            "dry_run", sa.Boolean(), nullable=False, server_default=sa.false(),
+        ),
+        sa.Column(
+            "started_at", sa.DateTime(timezone=True),
+            nullable=False, server_default=sa.func.now(),
+        ),
+        sa.Column("finished_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column(
+            "counts", postgresql.JSONB,
+            nullable=False, server_default=sa.text("'{}'::jsonb"),
+        ),
+        sa.Column("error", sa.Text(), nullable=True),
+        sa.Column(
+            "metadata", postgresql.JSONB,
+            nullable=False, server_default=sa.text("'{}'::jsonb"),
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("migration_run")

backend/app/models/__init__.py

@@ -10,6 +10,7 @@ from .image_record import ImageRecord
 from .import_batch import ImportBatch
 from .import_settings import ImportSettings
 from .import_task import ImportTask
+from .migration_run import MigrationRun
 from .ml_settings import MLSettings
 from .post import Post
 from .post_attachment import PostAttachment
@@ -40,6 +41,7 @@ __all__ = [
     "ImportTask",
     "ImportSettings",
     "MLSettings",
+    "MigrationRun",
     "TagAlias",
     "TagAllowlist",
     "TagReferenceEmbedding",

backend/app/models/migration_run.py

@@ -0,0 +1,37 @@
+"""MigrationRun — tracks each FC-5 migration invocation (backup/gs/ir/etc).
+
+kind/status are String(32) not Postgres ENUM so adding kinds later
+doesn't need a schema migration. The API layer validates values.
+"""
+
+from datetime import datetime
+
+import sqlalchemy as sa
+from sqlalchemy import Boolean, DateTime, Integer, String, Text, func
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column
+
+from .base import Base
+
+
+class MigrationRun(Base):
+    __tablename__ = "migration_run"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    kind: Mapped[str] = mapped_column(String(32), nullable=False, index=True)
+    status: Mapped[str] = mapped_column(String(32), nullable=False, index=True)
+    dry_run: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+    started_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(),
+    )
+    finished_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True,
+    )
+    counts: Mapped[dict] = mapped_column(
+        JSONB, nullable=False, default=dict, server_default=sa.text("'{}'::jsonb"),
+    )
+    error: Mapped[str | None] = mapped_column(Text, nullable=True)
+    metadata_: Mapped[dict] = mapped_column(
+        "metadata", JSONB, nullable=False, default=dict,
+        server_default=sa.text("'{}'::jsonb"),
+    )