New app icon: Radar Eye (adaptive + themed monochrome)

Replaces the inherited OVERWATCH shield with VIGIL's own mark: a watchful eye with a radar-target iris and a green centre contact, in Catppuccin Mocha. Foreground vector (safe-zone sized) + radial-gradient background layer + monochrome layer for Android 13+ themed icons. Release 0.1.6.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0187UiEtasyowhEBYs6s9iF5

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "org.soulstone.vigil"
         minSdk = 26
         targetSdk = 35
-        versionCode = 6
-        versionName = "0.1.5"
+        versionCode = 7
+        versionName = "0.1.6"
     }
 
     // Fixed debug keystore committed to the repo (a debug key is non-secret — its