Fix a thin or duplicate e-commerce category page without breaking faceted nav

You are an e-commerce SEO specialist fixing a category page that isn't earning organic traffic proportional to its product count.

CATEGORY PAGE: /shop/running-shoes — 84 products, gets some traffic on the base URL but almost none on any filtered combination
CURRENT CATEGORY COPY, IF ANY: (none — page is just a filter bar and a product grid, no text at all)
FACETED FILTERS AVAILABLE ON THIS CATEGORY: color, size, brand, price range, sort order (price/newest/rating), items per page
TARGET KEYWORD FOR THIS CATEGORY: men's running shoes

TASK

1. DIAGNOSE THE ACTUAL PROBLEM. State plainly whether the issue is (a) thin content — a grid of products with no unique text at all, (b) facet duplication — filter combinations like ?color=red&size=m generating near-duplicate indexable URLs against the base category, or (c) both. Don't default to "needs more content" if the real problem is technical duplication a content rewrite can't fix.
2. WRITE CATEGORY COPY that earns its placement — 150-300 words positioned above or beside the product grid, written for a category-level buyer question ("what to look for when buying X"), not a rehash of individual product descriptions. It must say something a shopper couldn't get by just looking at the product grid itself: a buying consideration, a sizing note, a common mistake, a way to narrow down which type of product fits which use case.
3. RECOMMEND AN INDEXATION RULE for the facets in color, size, brand, price range, sort order (price/newest/rating), items per page. For each filter type, say whether its resulting URL should be indexable, canonical back to the base category, or noindex+follow — a filter that changes the product set meaningfully and has real independent search demand (color, for a query like "red running shoes") is a stronger indexation candidate than one that doesn't (sort order, items-per-page).
4. FLAG PAGINATION HANDLING. State whether paginated category pages (?page=2, etc.) should be indexable in their own right, canonical to page 1, or handled with a "view all" alternative, based on whether /shop/running-shoes — 84 products, gets some traffic on the base URL but almost none on any filtered combination implies enough unique products per page to be worth indexing separately.
5. NAME ONE STRUCTURAL ELEMENT beyond copy that would help this category page specifically — a buying-guide-style FAQ block, a size chart, a comparison table across the category's own subtypes — and justify it against men's running shoes's actual intent rather than adding it reflexively.

OUTPUT
The diagnosis, the category copy in full, the facet indexation table (Filter type | Recommended treatment | Reason), the pagination recommendation, and the one structural addition.