feat: Nx BOM import — формат <qty>x <description>

Добавлен новый вариант импорта спеки: quantity-first формат, где каждая
строка начинается с `<qty>x <description>` (например, «2x Intel Xeon 8570»).
Порядок детекции: Inspur → Nx → Text BOM. Заголовок «, в составе:» работает
так же, как в Text BOM — последний токен перед запятой становится server_model.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible-local/09-vendor-spec.md

@@ -112,6 +112,41 @@ Rules:
 - lines that do not match `<description> - <quantity> шт.` are skipped;
 - no price data is present in the format; `unit_price` and `total_price` are left nil.
 
+## Nx BOM import (quantity-first)
+
+The same endpoint `POST /api/projects/:uuid/vendor-import` also accepts a quantity-first BOM
+where each item line begins with `<qty>x <description>`.
+
+Format: an optional header line ending with `, в составе:` followed by one component per line as
+`<qty>x <description>`. The `x` separator is case-insensitive; parentheses, commas, and hyphens
+inside the description are preserved as-is.
+
+Example:
+```
+Сервер G893-SD1-AAX3, в составе:
+1x 8U 2CPU 8GPU Server System (32x DDR5 DIMM Slots,8x 2.5" Hot-Swap Drive Bays, 4+4 3000W, 2x 10Gb/s RJ45, 2x IPMI RJ45)
+2x Intel Xeon 8570 (56 cores, 2.1GHz, 300MB, 350W)
+32x 64GB DDR5 ECC RDIMM
+1x GPU Nvidia HGX H200 141GB 8GPU
+3x 1.92TB NVMe PCIe SFF RI
+5x 7.68TB NVMe PCIe SFF RI
+8x 1-port 400G NDR OSFP CX7
+2x 2-port 100GbE QSFP56 CX6
+1x 2-port 10GbE RJ45
+```
+
+Rules:
+- the entire file becomes a single configuration (`server_count = 1`);
+- the header (any line ending with `, в составе:`) supplies `server_model` and `name`; the model is the
+  last whitespace-separated token before the comma;
+- without a header, `name` falls back to the uploaded filename (without extension) and `server_model` is empty;
+- the format carries no partnumbers — each line's description is stored as both `vendor_partnumber` and
+  `description`, so rows resolve through the active partnumber book when matched and otherwise stay
+  unresolved and editable in the UI;
+- lines that do not match `<qty>x <description>` are skipped;
+- no price data is present in the format; `unit_price` and `total_price` are left nil;
+- detection runs before Text BOM in the format switch (Inspur → Nx → Text).
+
 ## Pasted BOM text parsing
 
 `POST /api/vendor-spec/parse-text` is a stateless endpoint that parses pasted single-column text BOM
@@ -119,7 +154,7 @@ Rules:
 `{"rows": [{vendor_partnumber, quantity, description}], "format": "Inspur"|"Text"|""}`.
 
 This shares the exact detectors and parsers used by the file-import path
-(`ParsePastedBOMText` → `IsInspurBOM`/`parseInspurBOM`, `IsTextBOM`/`parseTextBOM`), so paste and upload
-behave identically — there is no second parser in the frontend. The configurator's BOM paste box calls
-this endpoint; an empty `rows` result (or any payload containing tabs, i.e. a real spreadsheet table)
-falls back to the manual column-mapping grid.
+(`ParsePastedBOMText` → `IsInspurBOM`/`parseInspurBOM`, `IsNxBOM`/`parseNxBOM`, `IsTextBOM`/`parseTextBOM`),
+so paste and upload behave identically — there is no second parser in the frontend. The configurator's BOM
+paste box calls this endpoint; an empty `rows` result (or any payload containing tabs, i.e. a real
+spreadsheet table) falls back to the manual column-mapping grid.