Payap model v2: bigger factory, shared plant room, separate water treatment

User, October 2026: the factory is too small and needs room to grow
(possibly ten more Classics), one shared hydraulic and air supply, water
treatment perhaps in a separate building connected to the galvanics lab,
and a fully equipped workshop (maintenance tools, 3D printers, maybe a
lathe and a small CNC mill).

Model (rebuilt live in FreeCAD 26.3, BIM objects, Params-driven,
parametric check plot 135->145 m and factory 112->120 m passed):
- plot 135 m (11.4 rai) with a reserve; factory 112 x 25 m, 16 bays,
  82 m visitor corridor, fire wall at 90 m;
- press hall ~870 m2: two Duplex systems (EX 50 + EX 35), the Classic,
  ten future Classic positions in two rows on a service trench;
- central hydraulics and compressed-air plant room (~62 m2);
- water treatment building 12 x 10 m behind galvanics: buried duct
  (gravity from the +1.2 m floor), covered crossing 6 m clear;
- workshop ~200 m2 with benches, tool cabinets, 3D printers, lathe,
  small CNC mill, drill, saw, welding bay, press, washer, measuring table.

Docs: galvanics (water treatment building, proposed), crane doc (workshop
fit-out; lathe and CNC mill not yet priced; corridor now 82 m),
site-candidates Payap section rewritten, README bullet.

docs/crane-workshop-tours.md

@@ -228,11 +228,26 @@ below the press hall in the pressure cascade.
   writing whether lifting a press into the workshop and back counts as a
   re-installation during the warranty period.
 
+### Fit-out (October 2026)
+
+The workshop is to be fully equipped for maintenance:
+- workbenches and the mould service bench, tool cabinets, hand and power
+  tools;
+- a workshop press, parts washer, pillar drill and band saw;
+- a screened welding bay and a measuring table;
+- **3D printers** for jigs, guards and small parts;
+- possibly a **lathe** and a **small CNC mill** to make and repair parts
+  in house.
+
+The [Payap scenario model](site-candidates.md#payap-scenario-model-october-2026) draws this set in a ~200 m²
+workshop next to the machine door.
+
 ### Rough cost (estimate)
 
 Workshop fit-out (benches, hand and power tools, hose crimper, parts
-washer, welding set and fume extractor, shelving, spill equipment, small
-machine tools if wanted): **1.0M to 2.5M THB (~30k to 76k USD)**. The
+washer, welding set and fume extractor, shelving, spill equipment, 3D
+printers): **1.0M to 2.5M THB (~30k to 76k USD)**. The lathe and the
+small CNC mill are not yet priced and come on top. The
 first spares stock sits in the existing working-capital line in
 [total investment](finance/total-investment.md).
 
@@ -304,8 +319,9 @@ The Payap scenario model
 resolves that conflict. Mastering and cutting, the offices and IT move
 into a separate office building, so only production sits under the
 crane. The tour then starts in the office building, at the cutting-room
-window and the listening room, and crosses a covered link into a 54 m
-corridor, inside the 45 to 55 m assumed below. The model also draws the
+window and the listening room, and crosses a covered link into an 82 m
+corridor. That is longer than the 45 to 55 m assumed below, because the
+press hall keeps room for ten more Classics. The model also draws the
 five-press fleet of October 2026; the sketch above still shows the
 earlier fleet (one Duplex and two Classics).