The CI postgres-test-discovery checker requires that PG-backed tests sit
inside a module whose name ends with `postgres_tests`. The two test
modules in admission.rs used names `pg_integration` and
`pg_orchestrator_integration`, which the checker rejects.
Rename:
mod pg_integration → mod postgres_tests
mod pg_orchestrator_integration → mod orchestrator_postgres_tests
Update the cross-module import accordingly. No behavioural change.
Verified: `scripts/test-postgres-test-discovery.sh` passes across all
401 Rust source files in the crates directory.
Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>