The trail survives a page reload

The self-recorded points now snapshot into localStorage per marker
(raw robot coords, so recalibration does not invalidate them). Restore
is gated: fresher than the linger window, same map, and never into a
run that started after the snapshot ended — the old trail must not
leak into a new cleanup. The smoke simulates the reload by wiping the
runtime map and asserts both the restore and the new-run discard.

docs/VACUUM.md

@@ -84,7 +84,7 @@ marker is edited as usual.
   Douglas-Peucker thinning, one SVG polyline.
 - Style fixed, no options: cartography casing — a dark translucent halo under a light core. Neutral (pure black/white alphas) and readable over any room fill; blend modes were rejected: each has a blind luminance where the line vanishes, and mix-blend-mode is costly on old kiosk WebViews. Lifecycle:
   appears on cleaning start, lives until dock + 10 min, dissolves;
-  `docked → cleaning` clears the old trail. Ephemeral, never stored.
+  `docked → cleaning` clears the old trail. Ephemeral on the server; the raw points snapshot into localStorage per marker so a page reload mid-run keeps the whole trail (freshness-gated by the same linger window; a new run or another map discards the snapshot).
 - Marker option «Показывать след уборки», on by default where data
   exists.