[Bug] PostgreSQL migration fails on restart: idx_reviews_user_date already exists

[mbeq]

Version: v0.7.2

When using PostgreSQL and restarting the server, the migration fails with: failed to initialize database: failed to execute schema file system_postgres.sql: pq: relation "idx_reviews_user_date" already exists.

In system_postgres.sql, the index idx_reviews_user_date is created without IF NOT EXISTS. All other indexes in the same file use CREATE INDEX IF NOT EXISTS. This makes the server impossible to restart when using PostgreSQL.

FIX: CREATE INDEX IF NOT EXISTS idx_reviews_user_date ON reviews(user_id, review_date);