[eagleoflqj]

App cards and detail sheets now share an icon cache, avoiding repeated downloads and retaining icons across app restarts. Cache entries use the release asset URL and recipe revision so a new build gets a fresh icon while catalog metadata changes reuse existing entries.

Decoded images use a 32 MiB NSCache target and a maximum edge of 256 pixels. Original image bytes use a 64 MiB disk LRU cache. Matching requests share a task, with at most four concurrent downloads; canceled views discard results without canceling other callers. Corrupt disk entries are fetched again, and persistence failures do not hide valid images.

Document both icon and existing index.json caching policies in docs/cache.md.

Validation:

• Release and Debug builds passed; all 14 Release tests and the Debug preview-scenario test passed.
• Strict swift-format and git diff whitespace checks passed; localization extraction left translations unchanged.
• Downloaded all 16 published icons through the cache, then verified all 16 in a fresh process with networking disabled.
• Verified native card and detail icon rendering from empty and warm disk caches.