The IndexedDB crypto store is evictable while the localStorage session survives,
so the browser can drop it out from under a live login -> the device resurrects
with a blank key store and re-uploads a one-time key at an id Synapse already
holds -> a permanent '400 M_UNKNOWN: One time key ... already exists' upload
storm (and undecryptable to-device/media keys downstream).
initClient now calls navigator.storage.persist() before creating the crypto
store, so the origin's storage is marked persistent and won't be evicted.
Best-effort (granted by engagement/PWA-install, no prompt; denial is non-fatal).
Preventive only -- an already-diverged device still needs a clean re-login.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
jaredandClaude Opus 4.8
45afc9ba7e