checkNotInMainThread was a debug-only Android assertion (Looper check behind BuildConfig.DEBUG).
Once the cache, feeds and view models moved to commons it could only fire through the
LocalCacheHost.assertNotMainThread hook, which is a no-op on every other front end, so it no
longer guarded the shared code it was sprinkled through. The checker, its call sites and the
host hook are removed; the two comments that explained a Dispatchers.IO switch by the assertion
now give the real reason (compression blocks).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S7FuNBSKiyVecARSoE4B9P