Payap scenario: parametric BIM model of the whole plant on a square plot

A separate FreeCAD 26.3 model (the Mueang Chi model is untouched) sites
the plant on a 110 m square placeholder plot of Payap land, built from
BIM objects (Arch Site, Buildings and Levels, walls, slabs, columns,
beams, a ramp, Spaces with computed areas, Equipment). Every object sits
on an expression-driven base, so the Params sheet drives plot, setbacks,
floor level, building sizes, fire wall line and office gap (checked:
plot 110 to 120 m and factory 84 to 90 m, everything followed).

- Factory 84 x 25 m, production only, in process order along a 54 m
  glazed corridor; press hall 465 m2 with the October fleet (two Duplex
  systems, each EX 50 + EX 35, and the Classic); crane to the fire wall;
  machine door and 12 m ramp at the north-west corner.
- Office building 24 x 15 m, 12 m away on its own slab with a covered
  link: reception, offices, meeting/training, mastering and cutting,
  listening, IT, archive. Resolves the crane-zone conflict of the old
  sketch.
- Utility yard behind the press hall (boiler and chiller flagged for
  re-sizing), gate, truck apron, car park, service road.
- site-candidates: new section and plot-fit note; crane doc: conflict
  resolved, 54 m corridor; README bullet and layout lines; the old
  sketch is labelled as Mueang Chi with the earlier fleet.

docs/crane-workshop-tours.md

@@ -297,6 +297,18 @@ conflict to resolve: with the workshop at the ramp end, reception and the
 cutting room sit under the bridge's travel too, against point 6 above
 (cutting room outside the crane zone).
 
+The Payap scenario model
+([cnx_vinyl_parametric_payap.FCStd](cnx_vinyl_parametric_payap.FCStd),
+[top view](cnx_vinyl_parametric_payap.png); see
+[site candidates](site-candidates.md#payap-scenario-model-october-2026))
+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
+five-press fleet of October 2026; the sketch above still shows the
+earlier fleet (one Duplex and two Classics).
+
 ### How it is built
 
 - **Room-in-room**: a glazed wall on the production side, a solid roof at