feat/show-filter-count

[ahuininga-orisha]

Summary

• Implements live product count updates on the "Show X items" button when tweakwise_layered_form_filters is enabled (issue Mobile filter - product count based on selection #302).
• On every filter checkbox change, a lightweight AJAX request is fired to tweakwise/ajax/productcount and the button label is updated without triggering a full navigation reload.
• The count endpoint is separate from the existing Navigation controller so no layout is rendered — only a Tweakwise API call and a JSON response.

How to test

Setup

1. Enable both tweakwise/layered/enabled and tweakwise/layered/form_filters in Stores → Configuration → Tweakwise.
2. Navigate to a category page that has Tweakwise facets, e.g. /women/tops-women/.

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Scenario 1 — Initial page load

1. Open the category page.
2. Each filter group should have a "Show X items" button whose count matches the total product count for that category.

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Scenario 2 — Single filter checkbox

1. Check one filter value (e.g. size M).
2. Without clicking the button, observe all "Show X items" buttons update to reflect the new count.
3. Verify the count matches what Tweakwise returns for that category + filter combination.

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Scenario 3 — Multiple filters combined

1. Check a second filter value (e.g. color Gray) while size M is still checked.
2. All buttons should update to the combined count (category + size M + color Gray).
3. Uncheck one filter; buttons should update back to the count for the remaining filter only.

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Scenario 4 — Full filter apply still works

1. Check a filter and click the "Show X items" button.
2. The page should navigate/reload with the filter applied as before.
3. After the AJAX navigation response, the button count should reflect product_count from the navigation response.

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Scenario 5 — formFilters disabled

1. Disable tweakwise/layered/form_filters.
2. Verify no count AJAX requests are fired on filter changes (the feature is inactive).