Plant assistant: one agent management and operators can ask

New docs/plant-assistant.md (decision, Alexander, 26 Oct 2026): an
assistant for the whole plant, asked in Thai or English at kiosks, desks
and phones, answering from the knowledge base (SOPs as ERPNext Quality
Procedures, vendor manuals on the Assets, recipes and limits, this
repository, lessons learned) and from ERPNext and the machine-data store,
with sources on every answer. Roles and questions, what it does
(explain, trace, summarise, alert context, plan vs actual, drafts) and
never does (machines, submitting, safety improvisation, seeing more than
the asker, rating operators, needing the internet). Built on Typhoon 2.5
(open weights, Apache-2.0, CPU trial first), Typhoon ASR for optional
voice, pgvector retrieval, MCP tools in cnx-factory through the one
integration layer and the PostgreSQL replica; vinyl-ai GPU server only if
needed (~250k to 300k THB, RTX 5090 Thai retail Oct 2026). Test set per
role, phasing, cost, risks, open decisions.

Mirrors: digital-factory systems and machines tables, rough cost note;
catalogue advisor becomes a role of the assistant; worker-safety
training; roadmap item 18; README bullet and layout.

docs/digital-factory.md

@@ -198,6 +198,7 @@ TODO list or small extensions to existing modules):
 | Plant core | Machine-data store (PostgreSQL for cycle and record rows, VictoriaMetrics + vmalert + Grafana for time series), Mosquitto, Telegraf persister, Alertmanager, factory application, file datasets on ZFS | `vinyl-core` | Build |
 | ERPNext | The system of record: accounting with Thai VAT and withholding tax, customers, prices, sales and purchase orders, artist gates, items, BOMs, work orders and job cards, stock and batches, quality inspections, metal parts and their genealogy, deliveries, assets and maintenance, payroll | `vinyl-erp` | from the first capex invoice; production records at commissioning |
 | Factory application | The tools and interfaces we build on ERPNext: station kiosks working the job cards, customer portal, machine-data service (cycles and per-record results in, totals and verdicts to ERPNext), instrument adapters, reports; the ERPNext integration layer. No business records of its own | `vinyl-core` | Build (v1), Launch (v2) |
+| Plant assistant | Management and operators ask in Thai or English; answers from the procedures, manuals and this repository and from ERPNext and the machine data, with sources; read-only, drafts records but never submits, never touches a machine ([plant assistant](plant-assistant.md)) | `vinyl-core` (CPU at first), `vinyl-ai` if a GPU is needed | Build (documents), Launch (kiosks) |
 | Edge collectors | Telegraf per machine zone, disk-backed store-and-forward, NTP to the OT segment, vision result receiver | `vinyl-edge-press`, `vinyl-edge-util`, `vinyl-edge-galv` | Build, Expand |
 | Environmental monitoring | Zone temperature, humidity, PM, differential pressure; alarms; correlation with production | RS485 loops into the edge collectors | Build |
 | Machine telemetry | Presses, extruders, hydraulics, boiler, chiller, compressor, heat pump, HVAC, PV, BESS, energy and water meters | edge collectors | Build |
@@ -304,13 +305,15 @@ Hardware classes are planning positions; models are chosen at purchase.
 | `vinyl-st-pack1` | Runout code camera read, jacket barcode scan, BOM check, barcode verifier | mini PC, camera, scanner, verifier | packaging |
 | `vinyl-st-ship` | Consignment assembly, carrier label and tracking capture | mini PC, label printer | shipping |
 | `vinyl-nvr` | Frigate CCTV recording on the cctv VLAN (optional; a vendor NVR appliance is the alternative) | small server with GPU or Coral accelerator | IT room |
+| `vinyl-ai` | The [plant assistant](plant-assistant.md)'s language model and speech recognition (optional; only if the CPU trial on `vinyl-core` is too slow) | server with one 32 GB GPU | IT room |
 
 Office audio intake and gate approvals happen from ordinary staff laptops
 on the `lan` VLAN through the same proxy; no dedicated machine. Stations
 run a kiosk browser (`cage` plus Firefox or Chromium) pointed at the
 application; badge readers and scanners are USB HID keyboard devices, so
 there is no driver work. Sixteen plant machines at launch, about twenty-one
-at maturity; every one is a directory and a line in the inventory.
+at maturity, plus `vinyl-ai` if the assistant needs it; every one is a
+directory and a line in the inventory.
 
 ## Networks
 
@@ -984,6 +987,10 @@ options, which come back with the quotes. Fleet pieces already paid for
 | Clan modules, router extensions, collectors, dashboards and rules to commissioning | 1 to 2 person-months |
 | Vision, metrology and audio pipeline integration (Launch and Expand) | 3 to 5 person-months, plus integrator fees in the vision quote |
 
+The plant assistant's GPU server, if it is bought, is costed in
+[plant assistant](plant-assistant.md#rough-cost-estimates), not in this
+total.
+
 Headcount note: [scale](scale.md) lists no IT or automation role in the
 15 to 25 people. Running this needs one automation and IT engineer from
 Build onward, part-time at launch; add it to the headcount.