feat(docs): добавлены правила коммитов COMMIT_RULES.md

- Зачем:
  - нужна единая спецификация для сообщений коммитов
  - облегчение code review и читаемости истории
- Что:
  - создан COMMIT_RULES.md с правилами Conventional Commits
  - адаптированы scopes под репозиторий: sql, modeling, bookings, docs, data
  - обновлена секция в AGENTS.md с ссылкой на полные правила
- Проверка:
  - git log --oneline -1
  - cat COMMIT_RULES.md | head -20

AGENTS.md

@@ -26,8 +26,10 @@
 - For `postgres-bookings`, after modifications run `docker compose up -d && ./psql_sh` and verify simple queries such as `SELECT COUNT(*) FROM bookings.flights;`.
 
 ## Commit & Pull Request Guidelines
-- Commit messages are short, imperative or descriptive phrases (often in Russian), e.g. `Добавлено оглавление`, `Переработка структуры`; group related edits into a single commit.
+
-- Pull requests should focus on one topic, include a brief context, list of changes, and manual steps to reproduce or validate (commands you ran, expected results).
+**Required:** Read [COMMIT_RULES.md](COMMIT_RULES.md) before making commits.
+
+Pull requests should focus on one topic, include a brief context, list of changes, and manual steps to reproduce or validate (commands you ran, expected results).
 
 ## Security & Configuration Tips
 - Do not commit personal `.env` files or credentials; use local overrides only.

COMMIT_RULES.md

@@ -0,0 +1,220 @@
+# Commit Rules
+
+Unified commit style for all project contributors. Follows [Conventional Commits](https://www.conventionalcommits.org/) specification.
+
+## Language
+
+- **Primary language**: Russian
+- If language is not specified, use Russian
+- For AI-generated commits, Russian is mandatory unless task explicitly sets `lang:en`
+- English is allowed only by explicit instruction (`lang:en`) or external collaboration requirements
+- Do not mix languages in free-text parts of one commit message (subject + body + footer)
+- Conventional Commit `type(scope)` stays in English
+- Technical terms (PostgreSQL, SQL, DWH, DDL, DML) keep as-is
+
+## Header Format
+
+```
+<type>(<scope>): <short description>
+```
+
+- Maximum header length: 72 characters
+- For Russian subject, use result form (e.g. "добавлено", "исправлено", "обновлено")
+- For English subject, use imperative present form (e.g. "add", "fix", "update")
+- For English subject, do not use past forms (e.g. "added", "fixed", "updated")
+- No trailing period
+- Keep subject specific; avoid vague messages like "update", "fix bug", "changes"
+
+### Allowed `type`
+
+| Type | Description |
+|------|-------------|
+| `feat` | New feature |
+| `fix` | Bug fix |
+| `refactor` | Code restructuring without behavior change |
+| `docs` | Documentation only |
+| `test` | Tests, checks, validations |
+| `chore` | Maintenance (configs, scripts, hooks) |
+| `ci` | CI/CD changes |
+| `perf` | Performance optimization |
+| `revert` | Revert previous commit |
+
+### Recommended `scope` for this repo
+
+| Scope | Used for |
+|-------|----------|
+| `sql` | SQL scripts in `dwh-modeling/sql/` |
+| `modeling` | DWH modeling docs, articles, schemas in `dwh-modeling/` |
+| `bookings` | Docker PostgreSQL demo in `postgres-bookings/` |
+| `docs` | Documentation, README, guides |
+| `data` | Data files (CSV, fixtures) |
+
+## Body Structure
+
+For non-trivial changes, body is required. Use bullet points for readability.
+
+Body is considered required when at least one condition is true:
+- behavior or API/contract changed
+- migration, rollback risk, or compatibility impact exists
+- more than one meaningful file/module changed
+- fix is non-obvious from header alone
+
+### Multiline body in CLI (important)
+
+- Do not pass body as one quoted string with `\n` (it will be stored literally).
+- Use multiple `-m` flags, or `-F` with heredoc.
+
+Correct:
+
+```bash
+git commit \
+  -m "feat(sql): добавлена валидация данных для DWH" \
+  -m "- Зачем:
+  - нужна проверка целостности перед загрузкой
+- Что:
+  - добавлен скрипт 04_validation.sql
+  - добавлены проверки на NULL и уникальность
+- Проверка:
+  - psql -f dwh-modeling/sql/04_validation.sql"
+```
+
+Also correct:
+
+```bash
+git commit -F- <<'MSG'
+feat(sql): добавлена валидация данных для DWH
+
+- Зачем:
+  - нужна проверка целостности перед загрузкой
+- Что:
+  - добавлен скрипт 04_validation.sql
+  - добавлены проверки на NULL и уникальность
+- Проверка:
+  - psql -f dwh-modeling/sql/04_validation.sql
+MSG
+```
+
+### Template (Russian - default)
+
+```
+<type>(<scope>): <краткое описание результата>
+
+- Зачем:
+  - причина изменения
+- Что:
+  - ключевое изменение 1
+  - ключевое изменение 2
+- Проверка:
+  - как проверено
+```
+
+### Template (English - only with `lang:en`)
+
+```
+<type>(<scope>): <short action description>
+
+- Why:
+  - reason for change
+- What:
+  - key change 1
+  - key change 2
+- Check:
+  - how verified (command/test/smoke-check)
+```
+
+## Commit Scope Rules
+
+- One commit = one logical task
+- Don't mix feature changes with large refactoring
+- Update docs in the same commit where behavior changes
+
+## Breaking Changes
+
+Use `!` in header for breaking changes:
+```
+feat(sql)!: rename stg_orders column contract
+```
+
+Add footer:
+```
+BREAKING CHANGE: column order_date renamed to created_at
+```
+
+## Examples
+
+### Good examples
+
+```
+feat(sql): добавлен скрипт загрузки DM-слоя
+
+- Зачем:
+  - нужны витрины для аналитики
+- Что:
+  - добавлен 06_dml_dm.sql с загрузкой фактов и измерений
+  - добавлены индексы для оптимизации запросов
+- Проверка:
+  - psql -f dwh-modeling/sql/06_dml_dm.sql
+  - SELECT COUNT(*) FROM dm.fact_orders;
+```
+
+```
+fix(bookings): исправлен порт в docker-compose.yml
+
+- Зачем:
+  - конфликт с локальным PostgreSQL на 5432
+- Что:
+  - порт хоста изменен на 5433
+- Проверка:
+  - docker compose up -d
+  - psql -h localhost -p 5433 -U postgres
+```
+
+```
+docs(modeling): обновлена схема Data Vault после ревью
+```
+
+```
+chore(docs): синхронизировано оглавление README
+```
+
+### Bad examples (don't do this)
+
+```
+❌ added sql script               # no type, past tense
+❌ feat: добавлен скрипт          # no scope
+❌ fix: исправлен баг             # no scope, vague and non-actionable
+❌ feat(sql): added new table     # past tense in English subject
+❌ feat(sql): add script and fix validation and update docs  # multiple concerns
+❌ feat(docs): add README и почини SQL # mixed languages in one message
+```
+
+## Quick Reference
+
+```bash
+# Feature
+feat(scope): добавлена новая возможность
+
+# Bug fix
+fix(scope): исправлена проблема
+
+# Documentation
+docs(scope): обновлена документация
+
+# Refactoring
+refactor(scope): упрощена структура без изменения поведения
+
+# Performance
+perf(scope): ускорено выполнение
+
+# Maintenance
+chore(scope): обновлены служебные настройки
+
+# Feature (lang:en)
+feat(scope): add new capability
+
+# Bug fix (lang:en)
+fix(scope): correct response parsing
+
+# Documentation (lang:en)
+docs(scope): update setup guide
+```