feat: обрезка КИЗ до 31 символа, README, инструкции для AI-агентов

- VBS и Python: в итоговом CSV код КИЗ обрезается до первых 31 символа
  (код без криптохвоста: 01 + GTIN + 21 + серийный номер); более короткий
  код остаётся как есть, с замечанием в отчёте. Копия kiz_to_csv.py в
  портативном комплекте обновлена так же.
- README.md: инструкция на русском, переписана проще и яснее;
  Инструкция_экспорт_CSV.docx пересобрана из того же текста, с настоящими
  заголовками и списками.
- AGENTS.md, CLAUDE.md, .agents/ (скилл kiz-testing, папки plans и reports).
- .gitignore для .DS_Store; .gitattributes хранит файлы без изменения
  концов строк (.bat и .vbs нужны CRLF).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -0,0 +1,39 @@
+# Project Rules
+
+These rules apply to every AI agent working in this repository, whatever the tool or model. The global rules in `~/.agents/AGENTS.md` apply too; the rules below are additional to them.
+
+## What this repo is
+
+Scripts that turn two Excel files into a CSV for upload to «Честный знак» (the Russian product-marking system), to take goods out of market turnover:
+
+- file 1 — the supplier's goods invoice (ТОРГ-12): goods from row 19, column B = product name + GTIN after the last space, K = quantity, L = price, N = VAT rate;
+- file 2 — the sheet of scanned КИЗ codes (DataMatrix marking codes) in its last filled column.
+
+The script matches each КИЗ to an invoice row by GTIN (`01` + 14 digits at the start of the code), fills columns B..G (name, price, `1`, `796`, VAT with `%`, `КИЗ`), cuts each КИЗ to its first 31 characters (the code without the crypto tail), checks quantities against column K, and writes `<name>.csv` and `<name>_report.txt` next to file 2. The Excel files themselves are never changed.
+
+User-facing instructions (Russian): `README.md`, and the same text in `Инструкция_экспорт_CSV.docx`. Keep both in sync.
+
+## Layout
+
+- `obrabotka_kiz_vb/xlsx_to_csv_utf8.vbs` — VBS version for Windows + Excel (uses Excel through COM). The file is **UTF-16 LE with BOM and CRLF line ends** — keep that encoding, otherwise Windows Script Host breaks the Cyrillic text. Edit it by decoding/encoding explicitly, not with tools that assume UTF-8.
+- `obrabotka_kiz_python/kiz_to_csv.py` — Python port of the same algorithm (openpyxl), with launchers `kiz_to_csv.bat` (Windows) and `kiz_to_csv.command` (Mac/Linux).
+- `obrabotka_kiz_python/KIZ_portable_Win7/` — portable kit for Windows without admin rights: embedded Python 3.8.10 + openpyxl, a copy of `kiz_to_csv.py` and `KIZ_CSV.bat`. Its `kiz_to_csv.py` must stay identical to `obrabotka_kiz_python/kiz_to_csv.py`.
+- Repo root `*.xlsx` — real sample files (`Куропятник.xlsx` is an invoice, `Книга1.xlsx` a КИЗ file, `УПД № 3602 ...xlsx` a УПД invoice). They are samples only; do not use them as test fixtures.
+
+## Rules
+
+1. The VBS and Python versions must behave the same and produce the same CSV. Every algorithm change goes into both (and into the portable copy of the Python script).
+2. The Python script must keep working on Python 3.8 (Windows 7 limit) — no newer syntax or libraries.
+3. Do not commit generated `.csv` / `_report.txt` files or test fixtures.
+
+## Where agent material lives
+
+- `.agents/skills/<name>/SKILL.md` — skills.
+- `.agents/plans/` — implementation plans. Name each file after what the plan implements.
+- `.agents/reports/` — reports and findings produced by executing a plan.
+
+## Testing
+
+When testing, always use the testing skill in `.agents/skills/kiz-testing/SKILL.md`.
+
+Whenever a plan is written, it must include a request to all AI agents implementing it to follow `AGENTS.md` principles (global and project) and to use the `kiz-testing` skill (`.agents/skills/kiz-testing/SKILL.md`) for all test work.