Fix label frame mapping and reference upscaling; add the stream G1 harness

Three defects, all found by scoring the live path against ground truth.

Inherited labels carried frame id 0. `_inherit_labels` set `label_box` but
never `label_frame_id`, so every inherited label was mapped back to the source
image with the first frame's offset. During a pan that puts the box a whole
pan-distance from the product it names, which is why most streamed tracks
matched no labelled facing. It now stamps the current frame and anchors to the
raw detection box rather than the smoothed track box, which lags a pan.

The reference lane upscaled views smaller than a pyramid level. `sku_l09.jpg`
is 407x305, so its 400 px level was a 305->400 blow-up: a blur with no
high-frequency detail to disagree with, which won 31 of 54 crops on the shelf
it was cut from. A view is now used only at the levels it actually has.

`score_stream.py` measured the wrong thing. It counted any facing touching the
window by one pixel (23 of 47 "in-catalog" facings were less than half
visible), scored a correct text-lane answer as a false accept because it
checked enrollment before correctness, and counted tracks rather than facings,
which reported 138% coverage of a 24-facing window. It now takes the union of
the window rects the client showed, keeps facings at least half inside, checks
correctness first, and reports facings named separately from labels correct.

Measured on add/image6.jpg, stock-lopia-clean, 20 s per run:

  pan  backend   facings named   precision
  0    van        11/24 (46%)     52%
  0    local      11/24 (46%)    100%
  2    van        12/24 (50%)     45%
  2    local      18/24 (75%)    100%
  12   van        11/24 (46%)     28%
  12   local      16/24 (67%)     83%

eval_identity on the same catalog is unchanged by the upscale fix (local 61%
end-to-end at 88% precision full, 59% at 95% live), and 1 of 602 distractor
crops from the 11 out-of-catalog shelf photos reaches 10 inliers, none reach 20.

recognization/code/identity_lanes.py

@@ -134,6 +134,14 @@ class LocalLane:
             if sku not in self.sku_ids:
                 self.sku_ids.append(sku)
             for height in heights:
+                if height > image.shape[0]:
+                    # Never upscale a reference. A 305 px view blown up to 400
+                    # is a blur, and a blur matches everything: the l09 shelf
+                    # crop won 31 of 54 crops on the shelf it was cut from, at
+                    # a median margin of 4.9, because its upscaled level had no
+                    # high-frequency detail to disagree with. A view is used at
+                    # the levels it actually has.
+                    continue
                 scaled = cv2.resize(
                     image,
                     (max(1, int(image.shape[1] * height / image.shape[0])), int(height)),