P6: placeholder icon, README, packaged build verified

- assets/icon.png (generated by scripts/make-icon.py) + icon.iconset
  (scripts/gen-iconset.sh); electrobun compiles it to AppIcon.icns
- branding.icon points at the iconset
- README: features, stack, dev/build, rebranding, plaintext-password warning,
  shortcuts, v1 scope
- verified: full production build (ng build + electrobun build) produces a
  launchable BunSCP.app that boots standalone from views://app

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/shared/branding.ts

@@ -4,5 +4,7 @@ export const BRANDING = {
 	appName: "BunSCP",
 	identifier: "es.teknes.bunscp",
 	version: "0.1.0",
-	icon: "assets/icon.png",
+	// macOS build converts this .iconset folder into AppIcon.icns.
+	// Regenerate from assets/icon.png with scripts/gen-iconset.sh.
+	icon: "assets/icon.iconset",
 } as const;