Splat spy: ship it to the App Store #3149

The owner thinks Splat spy (apps/splat-spray) could be a good App Store app. Since #3147 it has touch controls (a Scan / Pick switch, tap to fire, hold Scan to keep firing).

Still open:

• How to wrap it: the iOS shell route the other apps use (RustyBunsKit, packages/ios-kit) or a plain WKWebView of the online build.
• Apple signing is parked in MANUAL RUN: Apple-sign Agent Office (make the certificate on the other Mac), then try the auto-update #2441, and Xcode builds go to Bob, the builder Mac.
• Online play needs the edge deploy (bun run deploy) to stay up. Solo works offline.
• App Store review: a privacy policy, a sign-in that isn't required to play (eqosys is optional today), and screenshots.
• Performance: a phone GPU on the low quality tier (3000 splats per object) needs checking first. See the MANUAL RUN for the phone check.