fix(odds-ticker): publish the scroll cache array before the image

[ChuckBuilds]

Follow-up to #469, which merged while I was reviewing it. One finding, one line.

The problem

#469 moved the strip rebuild onto a worker thread — right call — but left _create_ticker_image writing the two helper fields image-first:

self.scroll_helper.cached_image = strip        # manager.py:2422
self.scroll_helper.cached_array = strip_array  # manager.py:2423

That is the reverse of the order the same PR established as correct in display()'s re-seed at 2982-2983, with a comment explaining exactly why:

Array first, then image. get_visible_portion reads cached_image.width and cached_array separately, so a new image against an old array is short by the difference.

_get_visible_portion_integer reads the two in separate statements:

img_w = self.cached_image.width
...
frame_array = np.ascontiguousarray(self.cached_array[:, start_x:end_x])

Why it is reachable now and was not before

It was safe while _create_ticker_image ran with display() blocked on q.get() — no concurrent reader. #469 removed that block. The rebuild now runs on a worker, and the new re-seed path deliberately keeps display() scrolling the previous strip while it runs, so the render thread reads in exactly that window.

Publishing ticker_image last does not protect it: that gate is already passed when the old strip is on screen.

Reproduced against the real ScrollHelper:

image=6392 array=6312, scrolled near the end
  ValueError: could not broadcast input array from shape (64,12,3) into shape (64,92,3)

image=6392 array=6392, same position
  ok, (128, 64)

Two adjacent statements, which is why #469's 30-minute soak saw none of it and reported zero not enough image data.

The test that should have caught it

test_ticker_strip_is_published_only_once_it_is_finished asserts min(publishes) > max(caches) — ticker_image after cached_array. It says nothing about the two cache fields relative to each other, so it passed throughout.

test_cached_array_is_written_before_cached_image walks both _create_ticker_image and display() in source order and requires every cached_image write to be preceded by a cached_array write. Against the pre-fix code it fails naming the line:

_create_ticker_image: cached_image is assigned at line 2422 without cached_array
being written first. A reader between the two sees a new image against an old
array and the slice is short. Write cached_array first.

Verification

odds-ticker tests 3 passed (7 assertions in test_display_defers_network), safety harness PASS at all 8 sizes, manifest gate OK. Manifest 1.4.3 → 1.4.4.

Not addressed here

_pump_background("image-rebuild", ..., min_interval=2.0) logs at INFO on every start, and a persistent no-games state leaves ticker_image None so it retries every 2s — roughly 30 INFO lines/minute for as long as it lasts. That is a large improvement on the per-frame warning it replaced (~6,000/min), so it is not a regression, but the data-update pump uses min_interval=30.0 and this one would read better at debug or with a longer backoff. Left alone rather than widening a one-line fix.

🤖 Generated with Claude Code

https://claude.ai/code/session_014RRtqXDCnvnY6EQwhT5CV9

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