Chasing full test coverage on a small system is a fantasy that eats the budget. The better question: which paths hurt when they break? Test those.
For a records system, that's the paths that touch money, official records, and data integrity, the submit that must not double-save, the report that must be correct, the migration that must not lose rows.
A handful of tests on the critical paths beats a suite of hundreds on the trivial ones. Coverage is a metric; confidence is the goal.
