Payap model: two-storey office building with canteen, changing and showers

User, October 2026: the office building also houses several showers, a
changing room, toilets and a canteen; the office area itself about
150 m2; the building can be multi-storey.

Model (office rebuilt live in FreeCAD 26.3; factory and site untouched):
- 32 x 15 m on two storeys (off_storey 3.6 m), ~960 m2 of floor, Arch
  Stairs plus a lift, first floor slab with the stair and lift void;
- ground floor: reception and lobby (entrance and link door), canteen
  ~40 seats with kitchen and servery, changing rooms women and men with
  4 showers each and lockers, toilets, mastering and cutting (acoustic
  lining), listening room, archive;
- first floor: offices 147 m2 (16 desks), training room (Payap
  programmes), meeting room, IT and server, toilets, pantry, flexible
  room;
- factory staff entry relabelled "PPE, WC" (changing is in the office).
New docs/cnx_vinyl_parametric_payap-office.png with both floor plans.

Docs: site-candidates Payap section (office bullet, staff entry, area
~3,400 m2 footprint / ~3,880 m2 floor), README bullet and layout line.

README.md

@@ -132,10 +132,12 @@ The detail lives in dedicated documents:
   [isometric](docs/cnx_vinyl_parametric_payap-iso.png)) of the whole plant
   on a square placeholder plot of Payap land: a 112 x 25 m production-only
   factory with the five-press fleet, room for ten more Classics and one
-  shared hydraulic and air plant, a separate office building for offices,
-  mastering and IT, a separate water treatment building next to
-  galvanics, the utility yard and site access, all driven by one
-  parameter sheet
+  shared hydraulic and air plant, a separate two-storey office building
+  ([floor plans](docs/cnx_vinyl_parametric_payap-office.png): canteen,
+  changing rooms and showers, mastering and listening below; ~150 m² of
+  offices, training room and IT above), a separate water treatment
+  building next to galvanics, the utility yard and site access, all
+  driven by one parameter sheet
 - [Process logging and traceability](docs/traceability.md): end-to-end
   per-order traceability for customers, batch genealogy from audio file to
   shipment, and the requirements this sets for the factory software
@@ -237,6 +239,7 @@ docs/
 ├── cnx_vinyl_parametric_payap.FCStd   Payap scenario parametric BIM model
 ├── cnx_vinyl_parametric_payap.png     Top view of the Payap model
 ├── cnx_vinyl_parametric_payap-iso.png Isometric view of the Payap model
+├── cnx_vinyl_parametric_payap-office.png Office building floor plans
 ├── crane-workshop-tours.md Overhead crane, workshop, visitor corridor
 ├── digital-factory.md     Data platform, NixOS/Clan fleet, acquisition, app
 ├── facility-security.md   Security, HVAC, fire and life safety, compliance