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.

docs/site-candidates.md

@@ -125,7 +125,7 @@ estimate.
   plot keeps a reserve in front for a second hall or a PV field.
 - **Factory, production floor only**: 112 × 25 m at floor level +1.2 m,
   16 frame bays, in process order along an 82 m glazed visitor corridor.
-  From west to east: staff entry and lockers; workshop and spares, with
+  From west to east: staff entry (PPE, WC); workshop and spares, with
   the machine door and a 12 m vehicle ramp at the north-west corner;
   galvanics clean room with a chemical day store; stamper prep, PVC lab,
   material area and the electrical room; the press hall; trim and optical
@@ -149,14 +149,24 @@ estimate.
   by gravity from the galvanics floor, and a covered crossing (6 m clear
   for trucks) joins the galvanics door
   ([galvanics](equipment/galvanics.md)).
-- **Office building, isolated from the factory floor**: 24 × 15 m, single
-  storey, 12 m south of the factory on its own slab and structure, joined
-  by a covered link that lands at the start of the visitor corridor.
-  - It holds reception, offices, a meeting and training room (the
-    [Payap programmes](payap-partnership.md)), mastering and cutting with
-    an inner acoustic lining, the listening room, the IT and server room,
-    the archive, and WC and kitchen.
-  - The lathe sits away from press vibration and outside the crane zone.
+- **Office building, isolated from the factory floor**: 32 × 15 m on two
+  storeys, ~960 m² of floor
+  ([floor plans](cnx_vinyl_parametric_payap-office.png)). It stands 12 m
+  south of the factory on its own slab and structure, joined by a covered
+  link that lands at the start of the visitor corridor. A stair and a lift
+  connect the floors.
+  - Ground floor, for staff and the studio: reception and lobby, a canteen
+    for about 40 with its kitchen, changing rooms for women and men with
+    four showers each, toilets, mastering and cutting with an inner
+    acoustic lining, the listening room and the archive. Staff change here
+    before crossing to the factory, whose staff entry keeps only PPE and a
+    WC.
+  - First floor: the offices (~150 m²), a meeting and training room (the
+    [Payap programmes](payap-partnership.md)), a meeting room, the IT and
+    server room, toilets, a pantry, and a flexible room for a second
+    classroom or more offices.
+  - The lathe sits on the ground slab, away from press vibration and
+    outside the crane zone.
 - **Utility yard** behind the press hall, across a 6 m lane:
   - boiler house with chimney and a covered fuel store;
   - chiller and cooling tower;
@@ -175,8 +185,9 @@ estimate.
   - a lane behind the factory serves the yard, the water treatment
     building and the ramp. The low-loader's swept path at the ramp still
     needs checking.
-- **Area**: about 2,800 m² of factory, 360 m² of office and 120 m² of
-  water treatment, so ~3,280 m² under roof plus the boiler house. That is
+- **Area**: about 2,800 m² of factory, 480 m² of office footprint (~960
+  m² on two floors) and 120 m² of water treatment, so ~3,400 m² under roof
+  plus the boiler house, and ~3,880 m² of floor. That is
   well above the 1,400 to 2,000 m² of the [scale](scale.md) zone table,
   which held one Duplex and an automated zone with the offices inside.
   - Two thirds of the difference is the press hall with its expansion