feat: add curriculum pair descriptions

docs: finalize local release documentation

fix(db): cascade group discipline dependents

feat: improve college group management

feat: improve college groups and tutoring workflows

fix: make submission file persistence atomic

feat: harden file storage and backup workflow

fix: use dedicated migration database role

feat: add PostgreSQL migration runner

feat: protect auth and isolate user stores

feat(tutoring): persist notes files and calendar

refactor(diagnostics): derive levels on server

feat(progress): use backend learning data

feat(lessons): show plans and homework in history

feat(homework): clarify assignment and submission cards

fix(layout): keep a single app scrollbar

refactor(homework): centralize lesson linking

feat(homework): link assignments to completed lessons

fix(homework): remove revision workflow

refactor(ui): require lesson plan before completion

refactor(ui): keep next lesson forms in card

docs: complete refactoring report

refactor: unify tutoring and homework flows

feat(plans): connect next lesson to occurrences