App 2.15.0: queued live data survives restarts

Unsent live samples were kept in memory only, so a reboot or a killed
process during a dead spot lost them. The queue is now saved to
files/telemetry_queue.json with AtomicFile, at most every 5 minutes and
only after a change (the flash is not written every 15 s), and at once
when the service stops; it is restored, oldest first and within the
2000-sample cap, when the service starts. A damaged file restores
nothing rather than failing. Tested on the emulator across a reboot.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

SPECS.md

@@ -83,7 +83,6 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
       write the file. To run more than one replica, first move Grafana to PostgreSQL or MySQL
       (`GF_DATABASE_TYPE`, `GF_DATABASE_HOST`, …); the replicas then share that database instead
       of a volume. The car data itself is in InfluxDB and unaffected.
-- [ ] **Telemetry queue survives restarts.** Unsent live samples are kept in memory only.
 - [ ] **EVHardware's comments are partly French.** About 120 comment lines in the vendored
       `EVHardware/` library (mostly `EVHardware.kt`, some tests), half-translated upstream. The
       app, the docs and the build files are English.
@@ -116,6 +115,11 @@ tyre pressures, GPS (lat, lon, elevation, heading) and the is_* flags. It does *
   INGEST_TOKEN) into git and pushed it. Commit amended and force-pushed; both values regenerated in
   the now gitignored `k8s/secrets.yaml` (since moved to `k8s/secrets/secrets.yaml`, outside
   `kubectl apply -f k8s/`). Filled-in secrets live only there from now on.
+- 2026-10-18 — App 2.15.0: unsent live samples survive a restart. The queue is saved to
+  `files/telemetry_queue.json` (AtomicFile) at most every 5 minutes and only after a change, and
+  at once when the service stops; it is restored, in order and within its 2000-sample cap, when
+  the service starts. A killed process loses at most 5 minutes. Tested on the emulator across a
+  reboot (6 queued samples back).
 - 2026-10-18 — App 2.14.4: every UI text is in `strings.xml` (Charging, Consumption and Settings
   labels, toasts, the trip-reset dialog, charging and Wi-Fi states, the daily summary, the "—"
   placeholder); lint reports no hard-coded text. Upload-log entries stay in code as log text.