GeezerVison

- Remove dead code: worker.connection.js, clientId, unused handlers
- Use metautil generateUUID for message and delta ids
- Server applies a batch of deltas with one save, stores deltas only
- Coalesce worker state saves, drop copies of freshly parsed data
- Handle cache update and clear results inline instead of self-events

- Server returns log length from chat/sync and emits chat/log with the
batch position to every client, the sender included: worker applies
entries in log order and pulls missed ones, so deltas sent offline no
longer move the cursor past deltas of other browsers
- Worker keeps ids of own deltas until the log returns them, instead of
every applied id; message deltas carry no reaction counters
- Worker is the only local replica: tabs render what it broadcasts,
without optimistic apply and dedupe
- Own deltas always go through the ordered persistent queue; sync after
connect no longer holds tab calls
- Server skips malformed deltas instead of failing the batch and chains
data file writes
- Bump static cache to v4