v0.1.4: fix silent failure on zones that reject ParkingEstimateMulti

Some zones (e.g. short-term "DL" spaces at the downtown lot) return
Response.Status:Error "Unable to process your request" for ParkingEstimateMulti
even though the single-duration ParkingEstimate works. The screen swallowed that
error -> empty duration list, disabled Pay button, no message ("nothing happens").

- Fall back to a single-estimate ladder across the zone's Min/Max time so these
  zones are purchasable (verified live: flat ~$0.10 up to ~33 min).
- Surface estimate errors with a message + Try again, instead of a blank screen.
- Log the estimate fallback/failure to the on-device diagnostics log.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/app.json

@@ -3,14 +3,14 @@
     "name": "BigBrainParking",
     "slug": "bigbrainparking",
     "scheme": "bigbrainparking",
-    "version": "0.1.3",
+    "version": "0.1.4",
     "orientation": "portrait",
     "userInterfaceStyle": "automatic",
     "newArchEnabled": true,
     "icon": "./assets/icon.png",
     "android": {
       "package": "top.mowden.bigbrainparking",
-      "versionCode": 3,
+      "versionCode": 4,
       "edgeToEdgeEnabled": true,
       "adaptiveIcon": {
         "foregroundImage": "./assets/adaptive-icon.png",