Press hall: five Duplex bays and four Classic positions (balanced at 60 % specials)

User (October 2026): "change the hall layout" after the finding that the
60/40 floor split leaves the Classics about half loaded at 60 %+
specials (specials run only on the Duplex systems).

- Press hall now keeps five Duplex bays (four along the visitor
  corridor, the fifth at the head of the second row) and four Classic
  positions: 550 + 200 = ~750 m2 of ~870 m2, ~73/27 by floor, 10 to 4 by
  presses; launch plant fills one of each, growth adds Duplex first.
- Full hall: ~2.9 to 4.4M records a year at 60 % specials, Classics ~80
  to 100 % loaded (60/40 gave ~2.3 to 3.6M); ~3.2 to 4.4M at ~20 %;
  fourteen presses as before: ~2.1 to 2.5 t/h steam, up to ~1.8 MW
  cooling, a utility phase of its own.
- pressing-line.md, scale.md, site-candidates.md, crane-workshop-tours.md,
  roadmap.md, README (FreeCAD model still the earlier layout, not
  redrawn); calculator preset "Full hall (5 D + 4 C)" and ladder; plant
  view reserves 5 Duplex bays and 4 Classic positions; business plan
  draft 0.2 rebuilt.

Checks: renderer 720 checks and functional checks pass, calculator
regression 0 fails, level checks clean; PDF 47 pages, TOC filled.

README.md

@@ -150,8 +150,8 @@ 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 128 x 25 m production-only
   factory with the five-press fleet, room for ten more Classics (drawn
-  before the October 2026 decision to lay the hall out 60/40 for Duplex
-  systems: four Duplex bays and six Classic positions), one
+  before the October 2026 decision to lay the hall out for Duplex
+  systems: five Duplex bays and four Classic positions), one
   shared hydraulic and air plant, a colour store with outdoor silos and a
   two-storey finishing and print block
   ([plans](docs/cnx_vinyl_parametric_payap-block.png)), a separate