Raw SQL and psql

prepare:psql passes psql arguments through while enforcing deterministic defaults and supplying the database connection itself.

Composite experiment

sqlrs prepare:psql -- -f init.sql run:psql -- -c "select count(*) from users"

• init.sql is resolved from the current working directory and must remain under the workspace root.
• The prepare stage fingerprints normalized SQL content, including supported include directives.
• The run stage uses the instance produced immediately before it.
• The ephemeral composite instance is discarded after the run finishes.

Connection arguments such as -h, -p, -U, and -d are rejected because sqlrs injects the connection.