entry(key, persist = true) and optimistic(key, update) silently defaulted
to persist:true after the first call for a key, and optimistic() didn't
accept a persist argument at all. Every current call site happened to be
safe, but the invariant was unenforced: a future caller invoking
store.optimistic() before any useCachedResource({persist:false}) has run
for that key in the same tick would silently start writing to
sessionStorage with no indication anything is wrong (T-02-01).
persist is now a required argument on both functions (no default), and the
per-key decision is recorded and asserted (dev-only warning) against any
later call that disagrees. useCachedResource's optimistic() wrapper now
threads its own already-resolved persist value through automatically, so
no existing composable caller changes behavior. The two call sites that
use the resources store directly (Cloud.vue/PeerFiles.vue's per-peer
browse cache) now pass persist:true explicitly, matching their existing
behavior exactly.
Co-Authored-By: Claude <noreply@anthropic.com>
