### Goal Find out how much of the code the tests cover, and use the result to decide where tests are missing. ### Findings so far - `package.json` has the script `test:coverage` (`vitest run --coverage`), but **no coverage provider** (for example `@vitest/coverage-v8`) is among the dependencies, so the script cannot work yet. - Many tests (the backend ones and the API tests) need a seeded database. 152 tests are skipped without one, so coverage must be measured with the database running. ### Checklist - [ ] Install a coverage provider as a dev dependency and configure it (include `src/` and `backend/src/`; exclude generated code, tests, and `src/components/ui/` where it is written by the shadcn CLI). - [ ] Run it with a migrated and seeded database; record the totals and the lowest files for the frontend and the backend. - [ ] Add tests for important code with low coverage (the calculator and the routine saving when they land; error paths). Do not chase a percentage: a test that does not fail when the code is broken counts for nothing (break the code on purpose to check). - [ ] Write the result in the README testing section: the command, the numbers, and what is deliberately not covered. ### Done when - [ ] `npm run test:coverage` works from a clean clone and the README says what it shows. _Text structured with Claude Code in discussion with Ronja. The original title is kept._