fix(android): resolve build errors in terminal scaffold

- Fix settings.gradle.kts: dependencyResolution → dependencyResolutionManagement
- Fix Hilt version: 2.54.1 (non-existent) → 2.51.1
- Fix LoyaltyApi.kt: remove decorative unicode comments causing
  "unclosed comment" errors, fix /api/v1/store/loyalty/* pattern
  in KDoc that Kotlin parsed as block comment start
- Add placeholder launcher icons (purple square, all densities)

App now builds and runs on Pixel Tablet emulator: Setup → PIN → Terminal.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clients/terminal-android/gradle/libs.versions.toml

@@ -34,7 +34,7 @@ room = "2.6.1"
 workManager = "2.10.0"
 
 # Dependency Injection
-hilt = "2.54.1"
+hilt = "2.51.1"
 hiltNavigationCompose = "1.2.0"
 
 # Camera & QR scanning