v0.1.6 — audit fixes (critical, moderate, minor) + UX polish

Critical
--------
- DetectionService: subscribe to threatLevel + top event flows; rebuild the
  foreground notification on every change so a locked-screen user sees
  escalations. Vibrate on upward tier transitions (escalating waveforms for
  YELLOW/ORANGE/RED), gated by Settings.vibrateOnAlert (default on).
- DetectionService: only mark _running=true if at least one scanner started;
  stopSelf() if everything was disabled or denied. Switch START_STICKY →
  START_NOT_STICKY so a system-killed service doesn't re-create into a
  stuck "running but not scanning" state.
- DeflockClient: detect Overpass timeout-in-body (`{"remark": "...timed
  out..."}`) and treat as failure — previously these 200-with-empty-elements
  responses got cached for 24 h, hiding ALPRs in that 5×5 km cell for the
  next day.
- DeflockScanner: record lastFetch coords + timestamp on BOTH success and
  failure, with a 60 s backoff window after a failed attempt. Previously
  `lastFetchLat` was only set on Success, so every subsequent location
  update would re-trigger a 30 s POST that collectLatest then cancelled —
  we'd never finish a fetch under sustained Overpass slowness.
- LocationProvider: stale-lastLocation race fix. The async `lastLocation`
  callback now only seeds `_location` if it's still null and we're still
  running — previously it could overwrite a fresher fix from
  requestLocationUpdates, or fire after stop() and resurrect _location with
  stale data.

Moderate
--------
- CitizenScanner: wait for the first non-null location with .first { } before
  starting the poll/delay loop. First Citizen poll now fires within seconds
  of the location fix, not up to 60 s after.
- MainScreen: when not running, show a muted gray circle with "IDLE" text
  instead of the same solid green look as "scanning, all clear" — the
  pulse animation was the only differentiator before.
- Compose state: rememberSaveable for the screen enum + bottom-sheet open
  state, so SETTINGS survives rotation.
- MainActivity: detect permanently-denied permissions (the user picked
  "don't ask again") via shouldShowRequestPermissionRationale. UI swaps the
  call-to-action to "Open app settings" which fires
  Settings.ACTION_APPLICATION_DETAILS_SETTINGS. onResume re-checks so a
  user returning from app settings is reflected immediately.

Improvements
------------
- BLE/WiFi scanners record SourceHealth.OK on a successful start (and
  FAILED with a specific reason on every short-circuit — disabled adapter,
  missing permission, etc.) so the drill-down sheet is honest about radio
  state, not just network state.
- DetectionEvent gains optional lat/lon (populated by DEFLOCK and CITIZEN);
  SourceRow shows a tap-to-open-Maps icon next to events with coordinates,
  firing a `geo:lat,lon?q=lat,lon(label)` Intent.
- SettingsScreen sliders use onValueChangeFinished — only commit to
  SharedPreferences on drag-release, not on every pixel of movement.
- New Settings.vibrateOnAlert toggle (default on) wired to a SettingsScreen
  row under a new "Alerts" section.

Minor
-----
- BleScanner iterates ALL manufacturer-data entries to find XUNTONG; only
  falls back to the first entry if no XUNTONG match is present. Previously
  we only inspected the first entry.
- Drop dead `?.` on JSONArray.optString in CitizenClient (returns String,
  never null).
- Remove unused rememberCoroutineScope in MainScreen.
- Update stale Phase/Waze references in DetectionService comments.
- Add VIBRATE permission to manifest.

versionCode 6 → 7, versionName 0.1.5 → 0.1.6.

app/build.gradle.kts

@@ -12,8 +12,8 @@ android {
         applicationId = "org.soulstone.overwatch"
         minSdk = 26
         targetSdk = 35
-        versionCode = 6
-        versionName = "0.1.5"
+        versionCode = 7
+        versionName = "0.1.6"
     }
 
     buildTypes {