fix(polygon): separate dataset sources from runs

docs/14_LIDAR_DATASET_GATEWAY.md

@@ -65,9 +65,12 @@ The gateway is not part of device quality diagnostics.
   dataset frames into the selected device evidence.
 - **Наблюдение** opens a concrete live or recorded spatial scene.
 - **Данные** owns source-of-record, retention, replay preparation and export.
-- **Полигон → Датасеты** lists admitted evaluation inputs.
+- **Полигон → Датасеты** lists admitted evaluation inputs and owns source
+  inspection: source sequences, sparse annotated scans and optional overlays
+  from a selected qualification run.
 - **Полигон → Прогоны** owns the resulting algorithm comparison, metrics,
-  provenance and decision.
+  provenance and decision. It does not present the dataset itself as a
+  simulation or continuous vehicle recording.
 
 Before real dataset bytes exist, the catalog explains the blocked storage gate
 and keeps `Открыть` / `Создать прогон` disabled. `Открыть` becomes available
@@ -341,9 +344,37 @@ qualification report:
 - deterministic `12,000`-point frame previews with remission, public
   point-aligned ground truth, Current and Patchwork++ masks;
 - compact size `67 MB`, versus multiple gigabytes for equivalent JSON;
-- `Play`, frame scrubber, a clickable all-frame delta strip, best/worst
-  ordering and direct modes for geometry, ground truth, both providers and
-  both error maps.
+- direct modes for geometry, ground truth, both providers and both error maps.
+
+The subsequent product review found a second semantic error: the `961` frames
+were presented as one playable recording. They are actually `8` independent
+GOOSE validation sequences:
+
+- `2022-07-22_flight` — `151` annotated scans;
+- `2022-08-30_siegertsbrunn_feldwege` — `103`;
+- `2022-09-21_garching_uebungsplatz_2` — `123`;
+- `2022-12-07_aying_hills` — `133`;
+- `2023-01-20_aying_mangfall_2` — `191`;
+- `2023-03-03_garching_2` — `106`;
+- `2023-05-15_neubiberg_rain` — `73`;
+- `2023-05-17_neubiberg_sunny` — `81`.
+
+Each admitted `.bin` is one annotated VLS-128 revolution. Within those eight
+sequences the validation scans are sparse: observed adjacent timestamps range
+from about `0.1 s` to `167.5 s`. The annotated ZIP contains neither a
+continuous playback stream nor a pose chain that could support visually
+continuous ego-motion. Mission Core therefore:
+
+- never plays across a sequence boundary;
+- labels Play as an accelerated scan review, not real-time playback;
+- exposes the exact source frame number and timestamp gap;
+- keeps a fixed sensor-centric origin and preserves the operator camera within
+  one sequence instead of refitting every frame;
+- does not interpolate missing scans or invent a route.
+
+Continuous vehicle motion, odometry and synchronized sensor playback require
+the separately admitted raw GOOSE ROS bags plus localization. Those assets are
+not part of the current `3.3 GB` annotated validation archive.
 
 The source archive and full-resolution crash-resume cache remain only on worker
 D. A bounded review mirror may be served by a Mission Core backend, but SSH is