feat: rename masq to snat throughout, update generator to Shorewall 5 snat format

backend/alembic/versions/0003_rename_masq_to_snat.py

@@ -0,0 +1,20 @@
+"""rename masq table to snat
+
+Revision ID: 0003
+Revises: 0002
+Create Date: 2026-03-01
+"""
+from alembic import op
+
+revision = "0003"
+down_revision = "0002"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.rename_table("masq", "snat")
+
+
+def downgrade() -> None:
+    op.rename_table("snat", "masq")