Plant and business plan calculator: configuration, investment, budget, ten-year cash

User request (October 2026): an interactive business plan calculator
where the plant configuration is chosen and everything follows. Built
into the fleet calculator (same page and URL, one model):

- Plant configuration card: galvanics in-house or bought stampers (and
  Pheenix estimate vs OMS reference), mastering and cutting in-house or
  outsourced, metrology full or launch tier, cassette and CD-R, solar
  buy / PPA / none, electric or biomass steam, Thai or Chinese utilities,
  crane buy or rent, visitor corridor now or later, ramp-up reserve;
  stamper supply to other plants; disabled-not-hidden controls.
- Investment built from the total-investment blocks (low / mid / high,
  sources and kind badges); boiler and chiller modules sized from the
  fleet and flagged past the four positions; phase 2 building past the
  870 m2 press hall. Default reproduces 160.9 / 226.7 / 292.5M THB.
- Budget card against 180M and 216M THB; "Investor levers" preset gives
  193.6M mid, 203.6 to 213.6M with the reserve.
- Money follows the configuration: outsourced title steps passed through
  at cost (fee split 51.1 / 37.0 / 11.9 %), electric steam energy and
  demand charge, PPA power price, optional cassette/CD-R revenue.
- Ten-year cash view: editable ramp and discount rate, payback, NPV, IRR,
  chart and table; pre-tax, pre-financing sketch.
- Presets: launch plant, investor levers, lean, five-press, full hall.
- Verified headless on Edge: 62 checks, 390 / 1024 / 1440 px, dark and
  light, no overflow, no page errors.

Business plan 9.4 cross-check updated to the calculator's figures
(EBITDA 1.68M, payback 4.1 yr; cash payback year ~5.7, IRR ~13 %);
docx and pdf rebuilt. README and landing entry renamed.

docs/business-plan/build/content_c.py

@@ -316,9 +316,12 @@ def blocks():
             "direct payroll and leaves out indirect labour (supervision, planning, warehouse), freight, scrap "
             "above the reject allowance and sales commissions. **Treat the adverse column as the honest one "
             "until those lines exist.**",
-            "**This is a sensitivity, not a forecast.** The press fleet calculator, with its own cost build-up, "
-            "gives a somewhat better central picture at 850k records: revenue 3.75M, EBITDA 1.82M, operating "
-            "profit 1.29M USD, payback 3.6 years. Not modelled: cassette and CD-R lines, stamper supply to "
+            "**This is a sensitivity, not a forecast.** The plant and business plan calculator, with its own "
+            "cost build-up (it adds electric steam heat and the cutting engineer, which this table leaves "
+            "out), gives at 850k records: revenue 3.75M, EBITDA 1.68M, operating profit 1.13M USD, payback "
+            "4.1 years on a mature year; with a ramp of 35, 70 and 90 % in the first three years, cash "
+            "payback in year ~5.7 and ~13 % IRR over ten years, pre-tax and pre-financing (estimates). "
+            "Not modelled here: cassette and CD-R lines, stamper supply to "
             "other plants, dropshipping fees, and the ramp year. BOI tax exemptions shield part of early-year "
             "profits where there are any.",
         ]),