Fall back to device id for Logger userId (#2319)

- Add PREFERENCE_KEY_DEVICE_ID and include it in BLACKLISTED_KEYS so the id stays device-local and never replicates through PreferenceSync
- Generate the id lazily via UUID.randomUUID on first need, persisted through the existing PreferenceManager string API
- Substitute the persisted id (prefixed "device:") for userId in Logger.log when no signed-in user email is available, so unsigned telemetry can still be grouped per install

🤖 Auto-generated

Co-authored-by: Owen McGirr <o.a.mcgirr@gmail.com>

Author: enaboapps

app/src/main/java/com/enaboapps/switchify/backend/preferences/PreferenceManager.kt

@@ -49,6 +49,7 @@ class PreferenceManager(context: Context) {
         const val PREFERENCE_KEY_MENU_SIZE_SCALE = "menu_size_scale"
         const val PREFERENCE_KEY_SETTINGS_TAB = "settings_tab"
         const val PREFERENCE_KEY_TELEMETRY_ENABLED = "telemetry_enabled"
+        const val PREFERENCE_KEY_DEVICE_ID = "device_id"
         const val PREFERENCE_KEY_ONBOARDING_CURRENT_STEP = "onboarding_current_step"
         const val PREFERENCE_KEY_ONBOARDING_USER_TYPE = "onboarding_user_type"
         const val PREFERENCE_KEY_ONBOARDING_IS_NEW_USER = "onboarding_is_new_user"
@@ -94,6 +95,7 @@ class PreferenceManager(context: Context) {
             PREFERENCE_KEY_SETUP_COMPLETE,
             PREFERENCE_KEY_REVIEW_LAST_SHOWN,
             PREFERENCE_KEY_TELEMETRY_ENABLED,
+            PREFERENCE_KEY_DEVICE_ID,
             PREFERENCE_KEY_GEMMA_TERMS_ACCEPTED
         )
     }

app/src/main/java/com/enaboapps/switchify/utils/Logger.kt

@@ -11,6 +11,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import java.net.HttpURLConnection
 import java.net.URL
+import java.util.UUID
 
 object Logger {
     private const val TAG = "SwitchifyLogger"
@@ -97,6 +98,7 @@ object Logger {
                     flowId = flowId,
                     stepIndex = stepIndex,
                     userId = AuthRepository.instance.getCurrentUser()?.email
+                        ?: "device:${getOrCreateDeviceId(prefs)}"
                 )
                 val payload = LogPayload(logs = listOf(entry))
 
@@ -126,4 +128,17 @@ object Logger {
             }
         }
     }
+
+    /**
+     * Returns a stable per-install identifier used as the userId fallback when no user
+     * is signed in. Generated once on first call and persisted; the key is blacklisted
+     * from sync so it never follows the account across devices.
+     */
+    private fun getOrCreateDeviceId(prefs: PreferenceManager): String {
+        val existing = prefs.getStringValue(PreferenceManager.PREFERENCE_KEY_DEVICE_ID)
+        if (existing.isNotEmpty()) return existing
+        val generated = UUID.randomUUID().toString()
+        prefs.setStringValue(PreferenceManager.PREFERENCE_KEY_DEVICE_ID, generated)
+        return generated
+    }
 }