feat(migrations): make podcast file_location nullable

surfsense_backend/alembic/versions/89_make_podcast_file_location_nullable.py

@@ -0,0 +1,46 @@
+"""Make podcast file_location nullable
+
+Revision ID: 89
+Revises: 88
+Create Date: 2026-02-03
+
+The podcast workflow creates a podcast record with PENDING status first,
+then fills in the file_location after audio generation completes. This requires
+file_location to be nullable.
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+
+revision: str = "89"
+down_revision: str | None = "88"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    # Make file_location nullable
+    op.execute(
+        """
+        ALTER TABLE podcasts
+        ALTER COLUMN file_location DROP NOT NULL;
+        """
+    )
+
+
+def downgrade() -> None:
+    # Set empty string for any NULL values before adding NOT NULL constraint
+    op.execute(
+        """
+        UPDATE podcasts
+        SET file_location = ''
+        WHERE file_location IS NULL;
+        """
+    )
+    op.execute(
+        """
+        ALTER TABLE podcasts
+        ALTER COLUMN file_location SET NOT NULL;
+        """
+    )