[JBorrow]

Fixes the production issue of product number being incorrect.

Co-authored with GPT 6.1 Sol

[Copilot]

🟡 Changes recommended

The related-collections query lacks a multikey index on collections.$id, causing a full Product collection scan on each applicable page request with cost growing across all stored product versions.

1 open issue

• Add an index on Product collections.$id to avoid full collection scans · New

What changed in this PR

Fixes incorrect product counts for parent and child collections by counting readable products directly rather than relying on hydrated links.

Changes:

• Adds an access-aware aggregation that avoids counting duplicate collection links.
• Passes computed counts to the collection-page template.
• Adds regression coverage for permissions, empty collections, shared memberships, and rendered counts.

File	Description
tests/​test_services/​test_collection_counts.py	Tests service counts and rendered results across access levels.
hipposerve/​web/​templates/​collection.html	Displays computed parent and child product counts.
hipposerve/​web/​__init__.py	Supplies related-collection counts to the template.
hipposerve/​service/​collection.py	Adds the access-filtered product-count aggregation.

_{Review effort: Balanced}