Expand test suite to 364 tests (168 unit + 196 E2E)

Unit tests:
- Volume/dilution calculation (63 tests): scaling, mode detection,
  ratio calculation, real recipe round-trip verification

E2E tests:
- Batch operations: create/tag/delete 3 recipes, adopt workflow
- Projects: CRUD, pricing, profit calculation vs oil costs
- Notifications: fetch, fields, mark-all-read
- Account settings: profile read/update, auth rejection
- Category modules: listing, tag reference
- Registration: register, login, duplicate rejection
- Audit log: pagination, field validation, action tracking

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

node_modules/.vite/vitest/da39a3ee5e6b4b0d3255bfef95601890afd80709/results.json

@@ -0,0 +1 @@
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