feat: add question insight analytics

ai_knowledge_base_v2/apps/backend/alembic/versions/0013_question_insight_indexes.py

@@ -0,0 +1,29 @@
+"""add question insight message index
+
+Revision ID: 0013_question_insight_indexes
+Revises: 0012_knowledge_latest_only
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "0013_question_insight_indexes"
+down_revision = "0012_knowledge_latest_only"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    _create_index_if_missing("sys_chat_message", "ix_chat_message_role_created", ["role", "created_at"])
+
+
+def downgrade() -> None:
+    indexes = {item["name"] for item in sa.inspect(op.get_bind()).get_indexes("sys_chat_message")}
+    if "ix_chat_message_role_created" in indexes:
+        op.drop_index("ix_chat_message_role_created", table_name="sys_chat_message")
+
+
+def _create_index_if_missing(table: str, name: str, columns: list[str]) -> None:
+    if name not in {item["name"] for item in sa.inspect(op.get_bind()).get_indexes(table)}:
+        op.create_index(name, table, columns)