GPS stop: import only the un-polled tail, not a full file re-scan

The old stop path re-added every native point "not already in the DB",
which raw-inserted points the live poll had intentionally dropped
(stationary / auto-pause / wrong state) with scrambled timestamps. The
detail view draws by seq order, so those late-written points with early
timestamps rendered as spikes across the map (distance stayed correct —
computeStats sorts by ts). Now stop imports only points past
_lastProcessedTs (the poll's processed marker): the genuinely un-polled
tail, including a screen-off stretch, without re-adding filtered points.

frontend/js/gps.js

@@ -1059,23 +1059,28 @@ GPS.stopRecording = async function() {
   let nativePointsFile = null;
   console.log(`[stop] enter nativeService=${GPS.recording.nativeService} sessionId=${GPS.recording.sessionId}`);
   if (GPS.recording.nativeService) {
-    // Import EVERY native point not yet in the DB. The live poll is screen-gated
-    // (WebView freezes timers while the screen is off), so a walk with the screen
-    // off leaves most points only in the native file. Idempotent by timestamp —
-    // same pattern as recoverSession. Then recompute stats over the COMPLETE set.
+    // Import ONLY the un-polled tail: native points with ts beyond the last one
+    // the live poll already PROCESSED (_lastProcessedTs). The poll advances that
+    // marker for every native point it handles, including ones it intentionally
+    // dropped (stationary / auto-pause / wrong state). The old code re-scanned the
+    // whole file and re-added everything "not in the DB" — which raw-inserted those
+    // dropped points back, interleaving them into the clean track and inflating
+    // distance with zigzag. Screen-off case still works: the poll was frozen, so
+    // _lastProcessedTs stays old and the whole dark stretch is beyond it.
     const nativePoints = await GPS._readNativePoints();
     let stopImported = 0;
     if (GPS.recording.sessionId && nativePoints.length) {
       const existing = await DB.getGpsPoints(GPS.recording.sessionId);
-      const dbTs = new Set(existing.map(p => new Date(p.ts).getTime()));
       let seq = existing.length;
       for (const p of nativePoints) {
-        if (dbTs.has(new Date(p.ts).getTime())) continue;
+        const pTs = new Date(p.ts).getTime();
+        if (pTs <= GPS.recording._lastProcessedTs) continue;
         seq++;
         await DB.addGpsPoint(GPS.recording.sessionId, p.ts, p.lat, p.lon, p.altitude, p.speed_ms, seq, null, p);
+        GPS.recording._lastProcessedTs = pTs;
         stopImported++;
       }
-      console.log(`[stop] native=${nativePoints.length} existing=${existing.length} imported=${stopImported}`);
+      console.log(`[stop] native=${nativePoints.length} existing=${existing.length} tail-imported=${stopImported}`);
       GPS.recording.points = await DB.getGpsPoints(GPS.recording.sessionId);
     } else {
       console.log(`[stop] SKIP backfill: sessionId=${GPS.recording.sessionId} native=${nativePoints.length}`);

src-tauri/Cargo.lock

@@ -139,7 +139,7 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "baldav"
-version = "0.1.382"
+version = "0.1.383"
 dependencies = [
  "base64 0.22.1",
  "btleplug",

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "baldav"
-version = "0.1.382"
+version = "0.1.383"
 edition = "2021"
 
 [lib]

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://raw.githubusercontent.com/nicegui/tauri-v2/refs/heads/main/tooling/cli/schema.json",
   "productName": "BalDav",
-  "version": "0.1.382",
+  "version": "0.1.383",
   "identifier": "dev.baldav.app",
   "build": {
     "frontendDist": "../frontend"