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/catalogue-intelligence.md

@@ -338,12 +338,12 @@ How it is kept honest:
   scored against the plain reorder rule; if it does not beat it, it
   becomes a report instead of an agent.
 
-**Which model runs it.** By the open-source rule, an open-weights
-language model served on a fleet machine (llama.cpp or vLLM on NixOS) is
-the default; the forecasting is ordinary statistics, so the language
-model only reads, searches and writes. No such GPU machine is in the
-fleet plan yet (estimate: one workstation-class GPU, a few thousand USD).
-A hosted model is a fallback to decide on only if the open one proves
+**Which model runs it.** The advisor is one role of the
+[plant assistant](plant-assistant.md): the same open-weights model on the
+plant's own machines, the same tool rules, with the catalogue tools and
+the catalogue roles' permissions added. The forecasting is ordinary
+statistics, so the language model only reads, searches and writes. A
+hosted model is a fallback to decide on only if the open one proves
 inadequate, and then only aggregates leave the fleet.
 
 ## How it fits the plant
@@ -386,7 +386,7 @@ inadequate, and then only aggregates leave the fleet.
 | Dashboard and sales map in the factory application | 1.5 to 3 person-months |
 | Forecast job: Stage 1 rule, then the Stage 2 model | 0.5, then 1 to 2 person-months |
 | Advisor: tools, prompts, logging, scoring | 1 to 1.5 person-months |
-| GPU machine for the open-weights model | a few thousand USD of hardware |
+| Language model and its machine | shared with the [plant assistant](plant-assistant.md#rough-cost-estimates) |
 | Map tiles, geocoder, hosting | on the existing fleet |
 
 ## Risks