feat(governance): unify durable event retention

database/versions/a6c8e2f4b1d3_3_0_11.py

@@ -0,0 +1,56 @@
+"""3.0.11 add retention cleanup indexes.
+
+Revision ID: a6c8e2f4b1d3
+Revises: e4f7a1b2c3d5
+Create Date: 2026-08-26
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision = "a6c8e2f4b1d3"
+down_revision = "e4f7a1b2c3d5"
+branch_labels = None
+depends_on = None
+
+
+_CLEANUP_INDEXES = {
+    "subscribehistory": (
+        "ix_subscribehistory_date_id",
+        ("date", "id"),
+    ),
+    "agentchat": (
+        "ix_agentchat_updated_id",
+        ("updated_at", "id"),
+    ),
+    "agenttaskrun": (
+        "ix_agenttaskrun_status_started_id",
+        ("status", "started_at", "id"),
+    ),
+}
+
+
+def _index_names(table_name: str) -> set[str]:
+    """读取实时索引名，兼容 fresh metadata 已创建当前索引的路径。"""
+    return {
+        index["name"]
+        for index in sa.inspect(op.get_bind()).get_indexes(table_name)
+    }
+
+
+def upgrade() -> None:
+    """为三张无界增长历史表补充保留期扫描索引。"""
+    table_names = set(sa.inspect(op.get_bind()).get_table_names())
+    for table_name, (index_name, columns) in _CLEANUP_INDEXES.items():
+        if table_name not in table_names or index_name in _index_names(table_name):
+            continue
+        op.create_index(index_name, table_name, list(columns), unique=False)
+
+
+def downgrade() -> None:
+    """删除保留期扫描索引，不改动任何历史数据。"""
+    table_names = set(sa.inspect(op.get_bind()).get_table_names())
+    for table_name, (index_name, _columns) in _CLEANUP_INDEXES.items():
+        if table_name in table_names and index_name in _index_names(table_name):
+            op.drop_index(index_name, table_name=table_name)