Make a record: investor demo of the artist platform, end-user flow

New static page docs/make-a-record.html (test site /demos/make-a-record/):
the artist platform as a customer would see it, polished for presenting.

- five steps (design, music and art, price, fan funding, track) with a
  sticky stage: to-scale mock-up (record spins at 33 1/3 or 45 rpm on
  hover), spec chips, price per copy, ship month and the next action
- design as option cards and swatches; options that do not apply stay
  visible and disabled (weight and gatefold off 12", colour pickers for
  black vinyl)
- masters and artwork read in the browser as in the detailed demo, side
  bars per side, checks in plain words, approval 1 of 3
- price with the curve, itemised lines folded under one summary, lead time
  as two bars (approvals, then the 7 to 9 week quote)
- fan funding: goal, break-even and what the artist keeps, money rules;
  the campaign on a phone with a pre-order ticker, funded or missed ends,
  production timeline with the artist's approvals, updates feed
- record passport for one delivered copy (stamper, press, cycle time and
  side; stage dates; optical inspection and sampled audio), per
  traceability.md and quality-automation.md, IDs simulated; repress card
- "Investor notes" switch with the business case per step (market
  research, vault, short-run economics and the Thai price gap, plant-owned
  vs broker and the Qrates lesson, traceability and represses); guided
  tour of about a minute (#tour, #notes in the URL)
- light/dark theme shared with the other pages; phone layout with a
  bottom bar

Same price list (demo-0.1) and stage table as artist-order.html, so the
defaults reproduce the artist platform example: 37,836 THB per title,
232 THB per copy at 100, break-even 41, goal 100, 548 THB kept a copy.

artist-platform.md: investor demo paragraph. traceability.md: the record
passport as the per-copy customer view. README bullet and layout line,
site DEMOS line and landing-page entry.

docs/traceability.md

@@ -53,7 +53,11 @@ For any order, the customer can follow the full chain:
   as the archive holds the metal parts.
 - **Customer-facing view**: traceability is a product feature, not an
   internal file. Customers get a per-order view (portal or report) covering
-  the chain above, without exposing other customers' data.
+  the chain above, without exposing other customers' data. The investor
+  demo [make a record](make-a-record.html) shows the per-copy version a
+  fan reaches from the code printed on the sleeve, the **record passport**:
+  stamper, press, cycle time and side, with the stage dates and the
+  inspection result (IDs simulated).
 
 ## Open design work