Add encrypted envelope recipient state

src/govoplan_postbox/backend/migrations/versions/a6d9e1f4c8b3_v013_external_recipient_tokens.py

@@ -0,0 +1,33 @@
+"""v0.1.3 external recipient token state
+
+Revision ID: a6d9e1f4c8b3
+Revises: f5c8d0e3b7a2
+Create Date: 2026-07-31 18:00:00.000000
+"""
+from __future__ import annotations
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "a6d9e1f4c8b3"
+down_revision = "f5c8d0e3b7a2"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("postbox_messages") as batch_op:
+        batch_op.add_column(
+            sa.Column(
+                "external_recipient_tokens",
+                sa.JSON(),
+                nullable=False,
+                server_default=sa.text("'[]'"),
+            )
+        )
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("postbox_messages") as batch_op:
+        batch_op.drop_column("external_recipient_tokens")