feat: SAC 0.7.0 display_name columns and event severity overrides

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/alembic/versions/010_event_severity_overrides.py

@@ -0,0 +1,29 @@
+"""event_severity_overrides table
+
+Revision ID: 010
+Revises: 009
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "010"
+down_revision: Union[str, None] = "009"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "event_severity_overrides",
+        sa.Column("event_type", sa.String(length=128), nullable=False),
+        sa.Column("severity", sa.String(length=16), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.PrimaryKeyConstraint("event_type"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("event_severity_overrides")