Press fleet calculator: target output and specials share to fleet mix and needs

User, October 2026: calculations for the later business plan, starting
from 2 Duplex + 1 Classic at 3 records a minute per Duplex and 2 per
Classic, as an interactive tool on the website: pick the yearly output
and the share of splatter/specials, get the machine mix and all the
requirements (people, hydraulics, power, ...).

docs/fleet-calculator.html (single static page, no dependencies):
- target mode sizes the fleet (specials only on Duplex with its EX 35;
  grow with Classics or with Duplex systems; start fleet as the floor);
  fleet mode takes a fleet and gives its output at the specials share;
- output, capacity, utilisation and the mix bar per machine type;
- needs: people per shift and in total, galvanics operators, machines,
  connected kVA and average kW, MWh/yr, central hydraulics (flow, motor,
  oil, accumulator), steam, cooling and cooling water, compressed air,
  press floor, room climate, compound, trim, titles, electroformed parts
  and plating units; checks against the 400 kg/h boiler, 250 kW chiller
  and the 870 m2 Payap press hall;
- ladder from the start fleet to a full Payap press hall, click to load;
- every assumption editable with its source (Newbilt Duplex site
  requirements V14 and offer 240620-04, scale.md, galvanics.md, revenue
  model, Payap model; estimates labelled), shareable link via the hash.
The Classic counts as one HRP 12 press plus one extruder until Newbilt
states figures (Toolex Alpha leaflet as a cross-check).

Site: DEMOS entry (/demos/fleet-calculator/) and landing-page entry.
README bullet and layout line; backlinks from scale.md (capacity) and
pressing-line.md (current plan).

docs/equipment/pressing-line.md

@@ -35,7 +35,12 @@ automated candidate). What it means:
   system 1: its hydraulic aggregate is already sized for the second press.
   The second press and the EX 35 complete system 1; system 2 and the
   Classic complete the fleet ([scale](../scale.md) capacity table,
-  [roadmap](../roadmap.md) item 24).
+  [roadmap](../roadmap.md) item 24). The
+  [press fleet calculator](../fleet-calculator.html) works out the mix of
+  Duplex systems and Classics for a target output and specials share,
+  with the utilities from Newbilt's site requirements; the Classic counts
+  there as one HRP 12 press plus one extruder until Newbilt states its
+  figures.
 - **One shared hydraulic and air supply.** A central hydraulic plant
   (pumps, tank, accumulators) and one compressed-air plant feed every
   press through ring mains, instead of a hydraulic unit per system. It