v1.16: simplify usage alerts to fixed 90% and 100% (less aggressive)

Replace the configurable threshold sliders with two fixed alert levels —
90% and 100% — per metric. Anti-spam now uses hysteresis instead of the
API reset-epoch (which could drift and re-fire): each level fires once
when crossed and re-arms only after usage drops back below it. Alerts are
posted only by the background worker, never the in-app refresh loop, so
you're not pinged while looking at the app. UI drops the sliders for a
one-line description; settings keep just the on/off switch.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/src/main/java/me/khodak/claudeusage/MainActivity.kt

@@ -103,43 +103,15 @@ class MainActivity : AppCompatActivity() {
 
     private fun setupNotificationSettings() {
         binding.switchNotify.isChecked = prefs.isNotifyEnabled()
-        binding.sliderSession.value = prefs.getSessionThreshold().toFloat().coerceIn(50f, 100f)
-        binding.sliderWeekly.value = prefs.getWeeklyThreshold().toFloat().coerceIn(50f, 100f)
-        applyThresholdLabels()
-        applyNotifyControlsEnabled(prefs.isNotifyEnabled())
-
         binding.switchNotify.setOnCheckedChangeListener { _, checked ->
             prefs.setNotifyEnabled(checked)
-            applyNotifyControlsEnabled(checked)
             if (checked) requestNotificationPermission()
         }
-        binding.sliderSession.addOnChangeListener { _, value, _ ->
-            prefs.setSessionThreshold(value.toInt())
-            applyThresholdLabels()
-        }
-        binding.sliderWeekly.addOnChangeListener { _, value, _ ->
-            prefs.setWeeklyThreshold(value.toInt())
-            applyThresholdLabels()
-        }
-
         // Alerts default on, so prompt for the runtime permission once on first launch
         // (a user who never toggles the switch would otherwise never be asked).
         if (prefs.isNotifyEnabled()) requestNotificationPermission()
     }
 
-    private fun applyThresholdLabels() {
-        binding.tvSessionThreshLabel.text = "Session alert at ${prefs.getSessionThreshold()}%"
-        binding.tvWeeklyThreshLabel.text = "Weekly alert at ${prefs.getWeeklyThreshold()}%"
-    }
-
-    private fun applyNotifyControlsEnabled(enabled: Boolean) {
-        binding.sliderSession.isEnabled = enabled
-        binding.sliderWeekly.isEnabled = enabled
-        val alpha = if (enabled) 1f else 0.4f
-        binding.tvSessionThreshLabel.alpha = alpha
-        binding.tvWeeklyThreshLabel.alpha = alpha
-    }
-
     private fun requestNotificationPermission() {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU) return
         if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS)
@@ -169,7 +141,8 @@ class MainActivity : AppCompatActivity() {
         val merged = fresh.mergedWith(prefs.getUsageData())
         prefs.saveUsageData(merged)
         prefs.recordHistory(fresh)
-        Notifier.checkAndNotify(this, prefs, fresh)
+        // Note: alerts fire only from the background worker, not here — no point pinging you
+        // with a notification while you're already looking at the app.
         updateUI(merged)
         ClaudeUsageWidget.notifyDataChanged(this)  // opening the app refreshes the widget too
         if (binding.tvDebugInfo.visibility == View.VISIBLE) {