Order tool v2: step-by-step configurator after mobineko.com/order

User, 19 Oct 2026: build a new version of the order tool like
mobineko.com/order; it should also offer selectable mastering like
brandenburgmastering.com at 60 USD a track.

- New docs/order.html (site /demos/order/): 15-step rail, step panel,
  large live SVG record (colour per disc, translucent, split, splatter,
  marble, colour-in-colour; label, dead wax, jacket view), floating
  quote card with price, ship window and quantity; phone strip and
  bottom bar. Review lists what is missing, itemised quote with basis
  badges, deposit, lead time, ERPNext touchpoints on the simulated
  order. Disabled-not-hidden options with reasons.
- Mastering choice: none, in-house vinyl mastering (5,000 THB a side,
  default), or partner studio (Brandenburg Mastering, Amsterdam, example,
  not contracted) at 60 USD a track (team figure), replacing the in-house
  line.
- Same R list and quote() as artist-order: defaults reproduce 37,836 THB
  per title and the per-copy figures; new lines (repress stamper,
  colour effects, printed inner, finish, obi, bag, shipping) are
  estimates.
- artist-platform.md: the page and the mastering choice; README, landing
  page and site/build.sh entries.
- Checks: pw_order.py 96 checks (parity, partner mastering, 15 steps at
  1440/1024/768/390 dark and light, disabled force-clicks, render sizes
  and fills, uploads, audio readers, share link, place order).

docs/artist-platform.md

@@ -51,6 +51,28 @@ after the URL, `#notes` for the notes) walks the whole flow in about a
 minute. It uses the same price list and stage table as the detailed
 demo, so a rate change goes into both pages.
 
+**Step-by-step order tool.** [Order a record](order.html) (test site
+`/demos/order/`, October 2026, after the configurator at
+[mobineko.com/order](https://mobineko.com/order)) is the order flow as a
+plant's online order form: a rail of numbered steps (order type, size,
+discs, vinyl colour and effects, labels, inner sleeves, jacket and
+finish, extras, mastering and cutting, test pressings, shipping, track
+list, artwork, review), each step's choices beside a large live picture
+of the record, and a running price and ship date. The review lists what
+is still missing before an order can be placed and links to fan funding
+in the detailed demo. It carries the same price list, so a rate change
+goes into all three pages.
+
+**Mastering as a choice** (user, October 2026): the order tool lets the
+customer pick the mastering: none (the master is final and only prepared
+for the lathe), CNX vinyl mastering in-house per side, or full mastering
+by a partner studio at **60 USD a track** (team figure, about 1,980 THB).
+The example partner is [Brandenburg Mastering](https://www.brandenburgmastering.com)
+in Amsterdam, which quotes on request and publishes no price list
+(checked October 2026); it is not contracted. Partner mastering replaces
+the in-house line rather than adding to it, and keeps gate 2: the artist
+approves the master before cutting.
+
 ## Why it fits this plant
 
 - **The bottom of the Thai market is unserved.** The one Thai plant we
@@ -103,7 +125,7 @@ their projects. See "Payments" below.
 | Jacket | None (customer supplies), plain, printed single, printed gatefold; printed by the local packaging partner |
 | Extras | Insert, hype sticker, shrink wrap, numbered edition, download card, barcode sticker |
 | Audio source | Digital files, analog tape (transferred in-house), or a lacquer cut by the customer's studio (straight to plating; must arrive within days of cutting) |
-| Audio services | Customer supplies a vinyl-ready master, or CNX vinyl mastering per side |
+| Audio services | Customer supplies a vinyl-ready master, or CNX vinyl mastering per side, or full mastering by a partner studio per track |
 | Metal | Lacquer cutting and stampers (in-house; bridge stampers from Stamper Discs until the galvanics line exists) |
 | Test pressings | Number of copies for the artist |
 | Delivery | Bulk to one address, dropship to each buyer, or collect at the plant |