ERPNext runs the whole plant; every tool we build integrates with it

Decided by the user (October 2026): the whole plant runs ERPNext, and
all tooling we develop has to interact with it.

digital-factory.md: standing decision in the summary; decision 10
(ERPNext owns the business documents, the factory application owns the
floor; ERPNext names are the shared keys); new section 'ERPNext: the
plant's ERP' with the ownership table (customers, prices, sales orders,
items and BOMs, work orders and job cards per station, batches and
quality inspections per compound lot, serial numbers for metal parts,
downtime entries, delivery notes, assets, accounting, payroll vs. cycles,
per-record inspection, genealogy and the hash-chained log staying in the
factory application), the integration rules (one typed Frappe REST
client in cnx-factory, an integration user per tool, webhooks in,
transactional outbox with idempotent postings so the floor never waits
on the ERP, business-sized postings, customisation as a Frappe app in
Gitea, nightly reconciliation, no public ERPNext endpoint, new tools use
the same client), hosting on NixOS (no nixpkgs module, NixOS/nixpkgs
#241921; Avunu frappe-nix as the start, frappe_docker as
oci-containers fallback; MariaDB + Redis; vinyl-erp on site behind the
gateway proxy; OIDC sign-on; upgrades on a restored copy), Thai
localisation (Ecosoft erpnext_thailand: VAT, WHT, PND, billing notes;
Ecosoft as partner to quote; payroll and BOI reporting to check),
phasing (dev ERPNext now; accounting and assets from the first capex
invoice; manufacturing at commissioning) and estimates. ERPNext added
to the architecture diagram, services, machines (vinyl-erp), module
list, backup, cost, build order and open decisions; the old 'ERP out of
scope, decide after launch' line replaced.

artist-platform.md: price list, customers, sales orders, campaign
pledges as payment entries, through the plant's outbox. traceability.md:
one ERP, one set of keys. README summary. total-investment.md added
scope: ERPNext (to quote, not in the sum, no licence fee).

docs/finance/total-investment.md

@@ -50,6 +50,7 @@ building, software and stamper prep lines, and the contingency on top).
 | Press fleet changed (October 2026) to two Newbilt Duplex systems (two presses each, EX 50 main extruder and EX 35 colour extruder) plus one Newbilt Classic, replacing the two blocks above (930k – 1,290k): Duplex system 1 as the first block (350k – 370k; the quote's second-extruder option becomes the EX 35), system 2 ~230k – 300k (two presses at the quoted ~115k per press and extruder set as the yardstick, plus hydraulic unit and EX 35, estimate; no EX 35 price on file), the Classic ~290k – 460k (the AD12 band per press as a placeholder; no Newbilt price on file) | −60k (low case) / −160k (high case) | −2.0M / −5.3M | estimate, [pressing line](../equipment/pressing-line.md); the Newbilt re-quote replaces it. The utilities for five presses are re-sized in the row below |
 | Utilities re-sized for the five-press fleet (October 2026): boiler bank 2 × 500 kg/h, chiller bank 3 × 250 kW with plate heat exchanger and tanks, larger softener and loop treatment ([steam and cooling](../steam-cooling.html)) | +185k (low case) / +294k (high case) | +6.1M / +9.7M | estimate, [utilities CSV](utilities-investment.csv) re-based from 24.0M – 41.6M to 30.1M – 51.3M THB |
 | Utility yard built for four boiler and four chiller modules (October 2026): yard ~379 m² against 178 m² ([scale](../scale.md#detached-utility-yard-parking-and-what-that-moves)) | 73k – 122k | 2.4M – 4.0M | estimate: the building rate above on the ~200 m² the yard grows by; the open chiller compound costs less than a building, so this is the cautious end. The valved branches and feeders for the empty positions are not priced yet |
+| ERPNext for the whole plant (October 2026): configuration with Thai tax, integration with every tool, Nix packaging; `vinyl-erp` server | to quote | to quote | not in the sum: 3 to 5.5 person-months in-house or a partner quote (Ecosoft), plus 2k to 4k USD hardware ([digital factory](../digital-factory.md#erpnext-the-plants-erp)); no licence fee |
 | Archive mobile shelving for the father and mother archive (October 2026) | to quote | to quote | not in the sum: A-Z Solutions publishes no prices; quote it and a Thai supplier ([facility security](../facility-security.md#archive-room-mobile-shelving)) |
 | **Added so far** | **~678k – 1,027k** | **~22.3M – 33.9M** | about 13 to 17% on the full-vision subtotal |