Solar on every roof, BOI solar correction, open source section

Solar (user, 17 Oct 2026: "use as much roof space as possible")
- PV on every roof and canopy: ~640 kWp on the Payap scenario plot
  (factory roof ~523, canopies ~54, flat office roof ~65 kWp around the
  AC units); ~300 kWp on the Mueang Chi hall. Calculator: pvKWp 640,
  new pvSelf 85 % (zero export, hourly sketch), PV cost per kWp times the
  array, office-roof PV in the iso view, roofs drawn full.
- 12.8M to 16.6M THB at 20 to 26 THB/W; CSV baseline 34.37M to 56.34M;
  launch plant ~168M / 231M / 294M THB with contingency; Plan B ~216M
  (label ~215M), ~39M above Plan A; Plan A unchanged (it leases the
  array), its solar lever ~17.5M. PV payback ~4.2 to 5.9 years.
- Permits (rooftop solar no factory licence since 28 Dec 2024, ERC
  exemption under 1,000 kVA, PEA zero export) and PPA discounts sourced
  in sustainability.md.

BOI correction
- Announcement 3/2568 (in force 1 July 2025) ended BOI promotion for
  solar installations; only the battery may qualify (12M THB per MW cap).
  Removed the "BOI solar measure" from boi.md, total-investment,
  revenue-model, sustainability, site-candidates and both plan versions;
  Plan B's case for owning the array is the PPA bill it avoids
  (~0.07M USD a year).

Open source (user, 17 Oct 2026)
- digital-factory.md "Open source throughout, and working with other
  plants": everything we run and build is open source on NixOS, our code
  published (licence to decide), vendor firmware the stated exception;
  later the stack and factory-automation services for other pressing
  plants, not in the revenue.
- Business plan section 5.6 plus an executive-summary bullet, reading
  guide and not-modelled mentions; draft 0.3 rebuilt (A 60, B 61 pages),
  renders re-made with the roofs full.

README.md

@@ -70,14 +70,14 @@ steps are open planning items.
 - The plant now launches with everything in one capital round (October
   2026): one Newbilt Duplex system and one Classic, a Pheenix galvanics
   line, the Sibert stamper-prep line, a Sillitoe cutting room and the
-  modular boiler and chiller plant: ~160M to 283M THB with contingency
-  (midpoint ~222M), the Pheenix line priced at OMS's reference plus 20 %
+  modular boiler and chiller plant: ~168M to 294M THB with contingency
+  (midpoint ~231M, PV on every roof and canopy), the Pheenix line priced at OMS's reference plus 20 %
   ([total investment](docs/finance/total-investment.md#launch-plant-october-2026)).
   For the investor the business plan comes in two versions, priced
   without contingency and with the ramp-up reserve
-  ([two plans](docs/finance/total-investment.md#two-plans-a-at-180m-thb-and-b-at-210m-thb-october-2026)):
+  ([two plans](docs/finance/total-investment.md#two-plans-a-at-180m-thb-and-b-at-215m-thb-october-2026)):
   **Plan A, ~177M THB**, the launch plant with six cost levers, and
-  **Plan B, ~208M THB**, the same launch plant with everything in.
+  **Plan B, ~216M THB**, the same launch plant with everything in.
   Chinese boilers, compressor and hydraulics save about 2M THB of that
   ([Chinese suppliers](docs/suppliers/china-utilities.md)).
   The business plan is re-based on it (draft 0.2).
@@ -171,7 +171,9 @@ The detail lives in dedicated documents:
   that has to exist for environment, machine, QC and genealogy data to land
   in one place keyed to one record identity, with ERPNext as the plant's
   only system of record (every tool we build reads and writes it; only
-  machine data stays outside): the plant as one more site in B4L's
+  machine data stays outside), everything open source with our own code
+  published and, later, the stack and automation services offered to
+  other pressing plants: the plant as one more site in B4L's
   existing NixOS fleet (the cnx-network clan: mesh, DNS, fleet
   monitoring, site gateway module, public proxy), what changes in that
   repo, VLAN zoning, Telegraf/MQTT acquisition source by source, QC
@@ -280,9 +282,9 @@ The detail lives in dedicated documents:
   output capacity, building area, land, electrical demand, solar and
   storage, steam and fuel, headcount, and money cross-references
 - [Total investment](docs/finance/total-investment.md): the launch plant
-  decided in October 2026 (~160M to 283M THB, ~4.85M to 8.6M USD, midpoint
-  ~222M THB) with the basis of every block, the two plans for the investor
-  (Plan A ~180M, Plan B ~210M THB, without contingency), and the earlier
+  decided in October 2026 (~168M to 294M THB, ~5.1M to 8.9M USD, midpoint
+  ~231M THB) with the basis of every block, the two plans for the investor
+  (Plan A ~180M, Plan B ~215M THB, without contingency), and the earlier
   answer to the 180M / 216M question; the earlier full vision and phased
   entry are kept as superseded
 - [Phase 1 construction RFQ](docs/finance/phase1-construction-rfq.md):
@@ -293,13 +295,13 @@ The detail lives in dedicated documents:
   planned 60 % specials (central revenue ~3.65M USD a year on ~0.74M
   records, EBITDA ~1.7M; the adverse case loses money), the operating
   pictures of Plan A (payback ~3.1 years on ~177M THB) and Plan B (the
-  same output, payback ~3.6 years on ~208M THB: its extra pays back
+  same output, payback ~3.8 years on ~216M THB: its extra pays back
   through what the table leaves out), the five-press table, and the levers and
   caveats behind the numbers
 - Business plan, draft 0.3 (October 2026), in two versions:
   [Plan A, ~180M THB](docs/business-plan/CNX-Vinyl-Business-Plan-A.pdf)
   ([docx](docs/business-plan/CNX-Vinyl-Business-Plan-A.docx)) and
-  [Plan B, ~210M THB](docs/business-plan/CNX-Vinyl-Business-Plan-B.pdf)
+  [Plan B, ~215M THB](docs/business-plan/CNX-Vinyl-Business-Plan-B.pdf)
   ([docx](docs/business-plan/CNX-Vinyl-Business-Plan-B.docx)): the
   investor-facing roll-up of everything above, each a complete plan with
   one table comparing it with the other, both priced without contingency