## Summary
A `/sessions` dashboard for inspecting durable Sessions, an `AGENT` /
`SCHEDULED` task-kind filter for the runs list, and the server-side
hardening (rate-limit exemption for packets, retry-with-backoff on
stream appends, typed too-large-chunk error) that the `chat.agent`
runtime in #3543 needs. Builds on the Sessions primitive shipped in
#3417.
## Design
The Sessions list + detail routes mirror the run inspector pattern.
`TaskTriggerSource` gains `AGENT` and `SCHEDULED` values, persisted on
`BackgroundWorker.taskKind` and `TaskRun.taskKind` (plus a matching
Clickhouse column), so the runs list can filter by kind.
New `@trigger.dev/core` modules — `sessionStreams`, `inputStreams`, a
`sessionStreamInstance` for realtime streams, and the
`realtime-streams-api` / `session-streams-api` surfaces — expose the
typed shapes that chat.agent will use to drive `session.out`.
`ChatChunkTooLargeError` lets the runtime drop oversized chunks with a
typed surface instead of failing the run. `s2Append` retries transient
failures with exponential backoff. `/api/v[12]/packets/*` is exempt from
customer rate limits so chat snapshot reads and writes don't get
throttled under load.
## Stack
Part of a 4-PR stack. Merge bottom-up.
1. **This PR** (#3542) → `main`
2. #3543 → #3542 — `chat.agent` runtime + browser transport
3. #3545 → #3543 — agent-view dashboard
4. #3546 → #3545 — ai-chat reference + MCP tooling
Replaces #3173 (closed).
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---
This is **part 5 of 5 in a stack** made with GitButler:
- <kbd> 5 </kbd> #3612
- <kbd> 4 </kbd> #3546
- <kbd> 3 </kbd> #3545
- <kbd> 2 </kbd> #3543
- <kbd> 1 </kbd> #3542👈
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Eric Allam
979655c281