Add CAC3 splash v2 (art/splash/).

Authoritative boot splash artwork for the CAC3 Qt wallet.

Files:
  - art/splash/splash-v2.jpg   (1254x1254, JPEG source of truth)
  - art/splash/splash-v2.png   (1254x1254, PNG lossless copy)
  - art/splash/README.md       (usage notes + future wallet wiring)

Composition: CAC3 medal mark (centered, gold reeded rim, grizzly bear +
lone red star on cream face), six California landmark photos in a 3x2+1
grid, CALIFORNIACOIN wordmark, CAC3 tagline. Red ground with gold/sunset
accents, unified sunset-golden-hour palette across all photos.

License: CC0 1.0 (public domain).

Downstream wiring (when C++ source lands):
  - src/qt/res/splash.png    (800x600)
  - src/qt/res/splash@2x.png (1600x1200)
  - src/qt/res/splash_testnet.png (future)

art/splash/README.md

@@ -0,0 +1,37 @@
+# CAC3 Splash Screens
+
+Boot splash artwork for the CAC3 (Californiacoin3) Qt wallet.
+
+## Files
+
+| File | Size | Purpose |
+|---|---|---|
+| `splash-v2.jpg` | 1254×1254, sRGB JPEG | Source of truth. Authoritative splash for v2 release. |
+| `splash-v2.png` | 1254×1254, sRGB PNG | Lossless copy of v2 (for tools that prefer PNG). |
+
+## v2 (current)
+
+- **Author**: Sami Ahmed (generated with AI assistance, 2026-07-15)
+- **Composition**: CAC3 medal mark (centered, gold rim with reeded edge, grizzly bear + lone red star on cream face), six California landmark photos in a 3×2+1 grid (Golden Gate, downtown LA skyline, Hollywood sign, Bixby Creek Bridge, lifeguard tower at sunset, classic lowrider, palm grove at dusk), `CALIFORNIACOIN` wordmark, `CAC3 — The Crypto for Real Riders` tagline.
+- **Palette**: Red ground with gold/sunset accents. Whole poster tied together by a unified sunset-golden-hour palette.
+
+## Wiring into the wallet
+
+When the C++ source lands, this image is the drop-in for the boot splash:
+
+| Wallet target | File to write |
+|---|---|
+| `src/qt/res/splash.png` (Qt boot splash) | convert `splash-v2.png` → resize to 800×600 → write |
+| `src/qt/res/splash@2x.png` (HiDPI) | 1600×1200 |
+| `src/qt/res/splash_testnet.png` | distinct splash for testnet (todo) |
+
+For now the splash is shipped as art only — wallet build wiring is a downstream step.
+
+## License
+
+Released under **CC0 1.0 Universal** (public domain dedication). Anyone may fork, recolor, or remix for downstream CAC3 implementations without attribution.
+
+## History
+
+- **v1** — six-landmark grid, red/gold poster. Superseded.
+- **v2** — current. Same author/composition family as v1, refined. Authoritative splash as of 2026-07-15.