Summary

Fix OpenlmisAppCacheController crashing when window.applicationCache is unavailable, which prevented the "Software last updated on" build date from rendering in the header.

Problem

The AppCache API (window.applicationCache) has been removed from modern browsers, so $window.applicationCache is undefined. $onInit called appCache.addEventListener before assigning vm.buildDate, throwing a TypeError and leaving vm.buildDate unset — so the build date never appeared.

Change

• Guard every access to window.applicationCache ($onInit listener registration and setUpdateReady). $onInit now completes and sets vm.buildDate; the cache-update flow safely no-ops when AppCache is absent.
• Add unit tests covering the missing-applicationCache case.

Testing

• grunt build: lint clean, all unit tests pass (946/946).
• Verified in reference-ui against uat.openlmis.org: the header shows the build date, e.g. "Software last updated on 16/07/2026"; console is clean, 4503/4503 tests pass.

Reference: originally fixed in the Eswatini distribution (OE-213), now moved upstream.