Launcher background: the starry sky over a magenta grid again, drawn by tools/make-title-art.py

The v0.5.6-alpha.5 gradient replaced a picture whose origin was not
recorded. The script now draws that look itself: a perspective grid fitted
to the old one's line positions (vertical lines within 2.4 px rms, the rows
within 3.8 px), its tile and line colours fading with depth as measured,
and about 2,500 stars placed by a fixed random seed with the old one's
count, sizes and brightness. The whole picture's mean colour is within one
level of the old one's.

The BC7 blocks now come from a mode 6 encoder in the script (49 dB against
the drawing, checked with Pillow's decoder), and the DDS header is
byte for byte the one the console has shown (4f633ad): the gradient's had
left out the mip count and straight alpha.

tooling/notices/components.json

@@ -183,7 +183,7 @@
       "copyright": ["pic0.dds, pic1.dds: Copyright (C) 2026 Mihawk, GPL-3.0-or-later (drawn by tools/make-title-art.py)", "snd0.at9: Copyright (C) 2026 BlackBearReloaded, GPL-3.0-or-later according to ps5-native-app-boilerplate's NOTICE.md"],
       "texts": [],
       "source": {"kind": "git", "path": ".", "remote": "https://github.com/mihawk-99/PS5_RetroArch"},
-      "modifications": "icon0.png is the RetroArch logo (libretro's branding); pic0.dds and pic1.dds are a gradient background drawn from nothing but arithmetic by tools/make-title-art.py in this repository (they replaced, in v0.5.6-alpha.5, a background whose origin was not recorded); snd0.at9 is ps5-native-app-boilerplate's default selection track."
+      "modifications": "icon0.png is the RetroArch logo (libretro's branding); pic0.dds and pic1.dds are a starry sky over a perspective grid, drawn from arithmetic and a fixed random seed by tools/make-title-art.py in this repository (they replaced, in v0.5.6-alpha.5, a background whose origin was not recorded); snd0.at9 is ps5-native-app-boilerplate's default selection track."
     },
     {
       "id": "fceumm",