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/roadmap.md

@@ -129,7 +129,9 @@ These three run in parallel and gate everything downstream:
     order in [digital-factory.md](digital-factory.md); the network, servers
     and edge collectors go in before the machinery arrives)
 18. Hire and train the launch team; safety program stands up with the
-    equipment, not after it
+    equipment, not after it. Procedures are written as ERPNext Quality
+    Procedures during commissioning, the knowledge base the
+    [plant assistant](plant-assistant.md) answers from
 
 ## Phase 4: Launch (the whole chain in-house)