feat(android): establish Jetpack Compose foundation with navigation and shared theme

- Set up project namespace to com.shieldai.android
- Add navigation-compose dependency
- Create ShieldAI brand color palette (Color.kt) with light/dark tokens
- Add Material3 Typography scale (Type.kt) with all text styles
- Create Shape.kt with small/medium/large rounded corners
- Implement ShieldAITheme with light/dark color schemes and optional dynamic color
- Define Screen sealed class with all destinations (Dashboard, Services, Alerts, Settings, Account, Login, Signup, Onboarding, ServiceDetail)
- Create NavGraph with composable routes and placeholder screens
- Implement BottomNavBar with 5 navigation items with icons
- Create AppNavigation with Scaffold, NavHost, and bottom nav visibility logic
- Add ShieldAIApp Application class and updated MainActivity
- Create vector drawables for bottom nav icons
- Add test files under new package
- Remove old template package (com.mikefreno.shieldai)

android/ShieldAI/gradle/libs.versions.toml

@@ -6,6 +6,7 @@ junitVersion = "1.1.5"
 espressoCore = "3.5.1"
 lifecycleRuntimeKtx = "2.6.1"
 activityCompose = "1.8.0"
+navigationCompose = "2.7.7"
 kotlin = "2.2.10"
 composeBom = "2025.12.00"
 
@@ -16,6 +17,7 @@ androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "j
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
 androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
 androidx-compose-ui = { group = "androidx.compose.ui", name = "ui" }
 androidx-compose-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }