migration: add author_id to messages

surfsense_backend/alembic/versions/63_add_message_author_id.py

@@ -0,0 +1,47 @@
+"""Add author_id column to new_chat_messages table
+
+Revision ID: 63
+Revises: 62
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+
+revision: str = "63"
+down_revision: str | None = "62"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    """Add author_id column to new_chat_messages table."""
+    op.execute(
+        """
+        DO $$
+        BEGIN
+            IF NOT EXISTS (
+                SELECT 1 FROM information_schema.columns
+                WHERE table_name = 'new_chat_messages' AND column_name = 'author_id'
+            ) THEN
+                ALTER TABLE new_chat_messages
+                ADD COLUMN author_id UUID REFERENCES "user"(id) ON DELETE SET NULL;
+                
+                CREATE INDEX IF NOT EXISTS ix_new_chat_messages_author_id
+                ON new_chat_messages(author_id);
+            END IF;
+        END$$;
+        """
+    )
+
+
+def downgrade() -> None:
+    """Remove author_id column from new_chat_messages table."""
+    op.execute(
+        """
+        DROP INDEX IF EXISTS ix_new_chat_messages_author_id;
+        ALTER TABLE new_chat_messages
+        DROP COLUMN IF EXISTS author_id;
+        """
+    )
+