perf(server): bound orchestration replay and slow-client live buffers

[leoisadev1]

Problem

WebSocket catch-up replay loaded a global event range and filtered per chat afterwards. A stale cursor, or a handful of large tool payloads, could decode gigabytes and OOM the server. Slow clients could also retain live shell and thread events without a memory bound, including the batch waiting for an RPC ACK. Recursive event-store page concatenation kept consumed pages alive.

Adaptation

Thread resume now measures and reads only that chat's rows through a captured head, with a 1,000-event cap and an 8 MiB serialized payload budget. A recreated chat ID falls back to a fresh snapshot. Shell resume still uses the global range, but it measures payload bytes in SQL before decoding and snapshots when the gap or budget is unsafe.

Live shell and thread subscriptions share a per-subscription budget that includes queued, coalescing, and unacknowledged work. Overflow detaches the producer even without another pull and returns OrchestrationGetSnapshotError so the client can resume from its last sequence. Event-store pages are released as they are consumed.

Akeru bot, group, channel, and people fields on the shell snapshot stay in place. Missing-chat errors still say Chat, not Thread. Clients that omit afterSequence still get a snapshot, including pre-pagination clients.

Upstream credits

Reviewed adaptations of T3 Code:

• #8992 bound replay payloads
• #9521 start live thread consumers immediately
• #9715 slow-client live budgets
• #9726 thread-scoped replay
• #10777 release consumed replay pages

Local #16 bootstrap replay, #143 coalescing, and #198 raw-observer policy are preserved. Provider adapters are unchanged.

Scope

Server wire/replay only. Client stream lifetime, config bootstrap, reducer reference stability, and static HTTP caching are separate PRs.

Verification

Focused tests:

• LiveStreamBudget, ThreadLiveEventCoalescer, OrchestrationEventStore, ProjectionSnapshotQuery replay stats: 17 passed
• subscribeThread/subscribeShell overflow, ACK retention, thread-scoped catch-up, recreated-ID snapshot, deleted-chat shell removal: 18 passed
• Mock-updated unit tests: 212 passed
• vp run --filter akeru-bot typecheck passed
• Targeted lint on changed files passed (one existing unused helper warning in server.test.ts)

Isolated web client, home /tmp/akeru-replay-verify.VTW8Fb, populated fixture, worktree ports 6892/14932:

• Paired into live BotThreadLanding at /bots/ui-scout. Scout chat, roster, reply/react/read-aloud, and composer rendered.
• Reload on the same chat kept /bots/ui-scout and the same messages, so reconnect resumed the subscription instead of an empty load.
• 390x844 viewport still showed the Scout chat and composer.
• Second pairing token opened a second browser session to the same environment and landed on the same Scout chat while the first session stayed live.
• Create → New group opened the live group dialog. The populated fixture has one bot and no groups, so Create group stayed disabled. GroupThreadLanding was not a loaded chat in this fixture.

These stills are the screens after those actions. They do not replace the pair, reload, second-client, and viewport steps above.

Limitations

This PR does not change provider adapters. Effect stays at beta.103; Stream.paginate is available locally. Native mobile was not required for this server change.

Grok 4.6 High in Grok Build via Orca.

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1 Skipped Deployment

Project	Deployment	Actions	Updated
akeru-bot-landing	Skipped		Sep 10, 2026 5:42pm UTC

[greptile-apps]

Greptile Summary

Summary

• Bounds orchestration replay by event range, event count, and serialized payload size.
• Falls back to snapshots when replay ranges are unsafe.
• Adds accounting for queued, coalesced, and unacknowledged live subscription events.
• Releases consumed event-store pages incrementally.
• Updates replay-stat test isolation to use the actual inserted sequence values.

No changes requiring attention were identified.

Confidence Score: 5/5

Safe to merge.

There are no outstanding findings requiring changes.

_{Reviews (2): Last reviewed commit: "test(server): bound replay-stat fixtures..." | Re-trigger Greptile}