Rework the Wallace tartan from a reference, and set it on the bias

The old sett was three flat stripes in roughly equal measure, which read
as a generic red-and-black check rather than as Wallace. Rebuilt against
a reference swatch.

- Setts are now written as a half-sett and reflected about their pivots,
  the way a threadcount is actually published, so the data stays in the
  form it is quoted in instead of a flat list kept symmetric by hand.
- Wallace is gold 6, black 6, red 36, black 24, red 36, black 6: a red
  ground at about two thirds, black bands alternating wide and narrow,
  and one thin gold overstripe per repeat. The reflection puts black on
  both sides of the gold line, which is what the reference shows.
- Colours taken from the swatch: a brighter scarlet and a stronger gold
  than before.
- Both the cloth and the icon are turned 45 degrees. The renderer draws
  well past the canvas edges so the corners stay covered once rotated.

The icon vector is generated from the same numbers rather than written
out by hand, so the icon and the splash cannot drift apart — changing
the sett rebrands both.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015qjfMiPUDshdKEUa6vxqzN

README.md

@@ -5,7 +5,7 @@ or against other people over Wi-Fi (LAN) or Bluetooth.
 
 ## What works today
 
-The app shell is complete and two games are playable end to end:
+The app shell is complete and four games are playable end to end:
 
 | | |
 | --- | --- |
@@ -59,9 +59,9 @@ them.
 
 ## Branding
 
-The launcher icon is a single square of the Wallace tartan, and the app opens on
-a tartan splash carrying the name in a Celtic uncial hand for two seconds before
-fading into the menu.
+The launcher icon is a single square of the Wallace tartan set on the bias, and
+the app opens on the same cloth carrying the name in a Celtic uncial hand for two
+seconds before fading into the menu.
 
 The tartan is drawn, not an image: `ui/theme/Tartan.kt` lays the sett down as
 warp and then as weft at half opacity, which is what produces the blended
@@ -70,12 +70,14 @@ drawable, so it stays sharp at every density and needs no PNGs.
 
 Two honest caveats:
 
-- **The sett is an approximation.** `WallaceSett` reproduces what the Wallace
-  tartan reads as — a bold red and black check divided by a narrow gold
-  overstripe — but the registered threadcount could not be verified, so the
-  numbers were chosen to look right rather than to be authoritative. They are
-  plain data; replacing them with the registered counts rebrands the whole app
-  and needs no other change.
+- **The sett is matched by eye, not to a registered threadcount.**
+  `WallaceSett` is written as a half-sett and reflected about its pivots, the way
+  a threadcount is published: gold 6, black 6, red 36, black 24, red 36, black 6.
+  That gives a red ground at about two thirds, black bands alternating wide and
+  narrow, and one thin gold overstripe per repeat flanked by black — matched
+  against a reference swatch rather than to the Scottish Register of Tartans.
+  Substituting registered counts is an edit to that one list; the icon is
+  generated from the same numbers, so both follow.
 - **The typeface is bundled under a licence.** Uncial Antiqua, © 2011 Brian J.
   Bonislawsky DBA Astigmatic, Reserved Font Name "Uncial Antiqua", used under
   the SIL Open Font License 1.1. The full licence is at