Artist ordering demo: configure, check, offer, fan-funded campaign

New static page docs/artist-order.html (test site /demos/artist-order/)
walking the artist platform flow end to end:

- record configurator (format, speed, discs, weight, colour, packaging,
  extras, mastering, test pressings) with a live mock-up
- track list or dropped masters read in the browser (WAV/FLAC/AIFF
  headers, sample peak and clipping), side length against the format,
  jacket and label preflight (size, dpi, CMYK), rights and gate 1
- itemised offer (per title / per copy, pass-through jacket), price per
  copy against quantity, lead time from the production timeline
- direct order or fan-funded campaign: goal = max(minimum run,
  break-even), what the artist keeps, the money rules, a simulated
  campaign (sells out / just makes it / falls short) with refund or
  go-ahead-at-minimum, and the production tracker with the three gates
  and the fan update feed

Price list demo-0.1 splits the doc's 38,000 THB per title and 132 THB per
copy into lines (estimates, each listed with its basis); defaults
reproduce the artist platform example (break-even 41, goal 100, ~548 THB
kept per copy at 100).

artist-platform.md: demo paragraph, side length per format table with
sources, VAT note on the campaign example. README bullet and layout line,
site DEMOS line and landing-page entry.

docs/artist-platform.md

@@ -24,6 +24,18 @@ vault and customer portal in [digital factory](digital-factory.md), and
 the dropshipping already in the fulfillment step. Every figure on this
 page without a source is an estimate.
 
+**Demo.** The [artist ordering demo](artist-order.html) (test site
+`/demos/artist-order/`) walks this whole flow on one static page:
+configure a record, type the track list or drop the master files and
+artwork (read in the browser and never uploaded: format, sample rate, bit
+depth, sample peak and clipping, side length against the format, print
+resolution and colour space), approve gate 1, get the itemised offer with
+its price curve and lead time, then order directly or set up a campaign
+and run it to a funded or a missed end, with the production steps and the
+three gates after it. Its price list (version `demo-0.1`) splits the
+illustration rates below into lines; every split is an estimate and the
+page lists each rate with its basis.
+
 ## Why it fits this plant
 
 - **The bottom of the Thai market is unserved.** The one Thai plant we
@@ -113,6 +125,31 @@ Transparency rules, so the word means something:
   currency choice the [revenue model](finance/revenue-model.md) already
   recommends deciding early.
 
+### Side length per format
+
+The audio check compares each side with the format's limit. Until the
+cutting engineer sets CNX's own figures, the demo uses published
+cutting-room guidance (checked October 2026):
+
+| Format | Comfortable | At most |
+|---|---|---|
+| 12", 33⅓ rpm | 18 min | 22 min |
+| 12", 45 rpm | 12 min | 15 min |
+| 10", 33⅓ rpm | 12 min | 16 min |
+| 10", 45 rpm | 8 min | 11 min |
+| 7", 33⅓ rpm | 5 min | 7 min |
+| 7", 45 rpm | 4.5 min | 6 min |
+
+Source: the microcut.studio format guide
+(https://microcut.studio/guides/vinyl-format-guide-12-10-7/, lower end of
+each range). Diggers Factory lists hard maxima of 22, 12, 17, 10, 6 and 5
+minutes for the same formats (stricter on 12" at 45 rpm), and A to Z Media
+14 to 18 minutes as ideal on a 12" LP. Loud or bass-heavy music needs
+shorter sides: Diggers Factory's dance-music figures are about 60 % of its
+standard ones (11:27 against 19:23 on a 12" LP), which the demo applies as
+a factor of 0.6. The engineer check, not this table, decides whether a
+side is cuttable.
+
 ### What it looks like with numbers
 
 An illustration of the **shape**, using the midpoints of the working
@@ -199,6 +236,11 @@ about **799 THB**, because the per-title cost spreads. The calculator
 shows the artist this before launch, for any price they type in. Shipping
 is charged to the fan separately at checkout, at cost.
 
+VAT is not in this example. With CNX as seller of record (open decision
+1), a 1,200 THB fan price includes about 79 THB of VAT (7/107), which
+comes out of the artist's margin; the demo can show the numbers with and
+without it.
+
 Over-subscription is good news: the run is pressed at the final number
 plus the artist's own copies and the spares the reject allowance already
 covers. An artist can cap a campaign for a limited, numbered edition.