## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work
> - Every master push publishes a canary through release-verify; the
staging fleet and the nightly/beta/stable chain start from those
canaries
> - The server suite grew substantially on 2026-09-10 and now runs under
real contention in CI, where three tests assert timing properties that
only hold on an idle machine
> - Each of the three failed a release-verify canary run that day (runs
34497348802 and 34517515849), and together with the shard timeouts
(#13185) they kept any canary from publishing after 18:50 UTC
> - This pull request makes the three assertions contention-tolerant
without weakening the invariants they prove
> - The benefit is a canary lane whose verdicts reflect the code, not
the load on the runner
## Linked Issues or Issue Description
**What happened?**
Three server tests failed release-verify canary runs on 2026-09-10 under
CI load:
1. `chat-channels.integration.test.ts › returns a retryable webhook
failure when the delivery insert fails before durable receipt` — the
duplicate-redelivery request drew the retryable 503 instead of an
immediate 200 (run 34517515849).
2. `chat-channels.integration.test.ts › returns ephemeral guidance for
exact Slack controls in channels without creating tasks or actions` — a
`provider_effect` row was read before its async settlement reached
`processed` (run 34497348802).
3. `runner-connection-eval-fixtures.test.ts › resets paired attempts…` —
the fixture's `TRUNCATE companies CASCADE` was chosen as a deadlock
victim (40P01) against the helper app's own background sweeps (run
34497348802).
**Expected behavior**
Verify runs fail only for real regressions. A momentary-contention 503
on a duplicate redelivery, an in-flight settlement row, and a
deadlock-victim reset are all recoverable states the code handles by
design.
**Steps to reproduce**
Run the three tests under a loaded 3-shard release-verify split; the
timing assertions flake. Under `pr-trusted`'s lighter shards they
usually pass, which is why the PRs that introduced them were green.
**Paperclip version or commit**
`master` at `d1ba17eec`.
## What Changed
- The duplicate-redelivery assertion retries on 503 the way Slack itself
would (bounded, 250 ms apart), then asserts the 200 and the unchanged
dedup invariants: duplicate count increments, still exactly one issue.
- The channel-controls settlement read is wrapped in a bounded
`vi.waitFor`, the same pattern the file's durable-receipt paths already
use.
- The runner eval fixture retries its TRUNCATE on Postgres error 40P01,
bounded at five attempts, and rethrows anything else.
## Verification
- All three run green locally: the two chat tests via `-t` filters, the
eval fixtures file in full (6 tests).
- Each change is assertion-shape only; no product code is touched.
- Observation for a follow-up, not this PR: the chat integration file
costs ~15 s transform + ~28 s import per vitest worker before any test
executes — splitting it would give back real shard time.
## Risks
- Low risk: the retries and waits are bounded, so a genuine regression
(permanent 503, settlement that never lands, persistent deadlock) still
fails within the same timeouts as before.
## Model Used
- Claude (Anthropic), model ID `claude-fable-5` (Claude Fable 5),
extended thinking, tool use via Claude Code CLI.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
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