Honest ring feedback (write-ACK != actually ringing)

The DULT/FMDN path reported 'Ringing…' off the GATT write acknowledgement, not the tag's real response — so a tag that ACKs but declines to ring (e.g. because it's not separated from its owner) still showed success. Reworded to 'Ring command sent — a tag only chirps when separated from its owner.' Release 0.1.5.

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 = 5
-        versionName = "0.1.4"
+        versionCode = 6
+        versionName = "0.1.5"
     }
 
     // Fixed debug keystore committed to the repo (a debug key is non-secret — its