## Summary
Three fixes to the run-ops database split (the Cloud-only mode where
run-lifecycle rows live on a dedicated Postgres). All are inert in the
default single-database deployment.
The main fix: on the batch trigger paths, a parentless batch's item runs
chose their physical store from a fresh per-org mint-flag read at
processing time, so flipping an org's flag mid-batch could land an item
in a different store than its batch, breaking the `TaskRun.batchId`
foreign key (or silently orphaning the item). The other two harden the
split's safety nets: the schema-parity test now actually compares
columns, and the read fan-out gate now signals when it has been silently
disabled.
## Batch item residency
`RunEngineBatchTriggerService` (api.v2) and the BatchQueue item callback
(api.v3) now anchor each item's id mint on the batch's own friendlyId,
mirroring the already-safe `BatchTriggerV3Service`. Residency is a pure
id-shape check, so an item can no longer diverge from its batch across a
mid-batch flag flip. The pre-failed-run fallback is anchored the same
way (it also sets `batchId`), and the shared mint branch is consolidated
into one helper so every mint path stays in lockstep. No new database
queries; single-database mode is unchanged (a cuid-shaped batch
friendlyId yields a cuid item).
## Schema parity test
The parity test previously read only the dedicated schema and matched
model headers with regexes, so it never compared columns and could not
catch a run-subgraph column that diverged between the two physical
schemas. It now parses both schemas and asserts bidirectional
scalar-column parity (type, nullability, array-ness, default) across the
run-subgraph models, and fails on any field line it can't parse. Scoped
to the run-subgraph models so unrelated control-plane edits don't break
it.
## Read fan-out signal
The split read fan-out gate is decided by the object identity of the NEW
vs control-plane clients. It now warns when both run-ops URLs are set
but the NEW client isn't a distinct instance (fan-out silently off), and
a new test exercises the real topology-into-gate wiring so a future
refactor that aliases the clients can't disable fan-out unnoticed.
## Verification
New unit and glue tests cover all three changes; the DB-backed
residency, store-routing, and topology suites pass against real
Postgres; `typecheck` is clean for both packages.
## What
Wires the run-ops split into the webapp: database topology, environment
flags, split-mode gating, and the control-plane resolver/cache layer
that the run-store and run-engine seams from the previous PR plug into.
- **DB topology & env** (`apps/webapp/app/db.server.ts`,
`env.server.ts`, `entry.server.tsx`): adds the run-ops database
clients/topology and the environment variables that configure and gate
the split.
- **runOpsMigration module** (new
`apps/webapp/app/v3/runOpsMigration/`): the webapp-side machinery —
`splitMode.server.ts`, `controlPlaneResolver.server.ts` +
`controlPlaneCache.server.ts`, `readThrough.server.ts`,
`crossSeamGuard.server.ts`, `distinctDbSentinel.server.ts`, id-minting
helpers (`mintBatchFriendlyId`, `runOpsMintKind`,
`resolveInheritedMintKind`), `runOpsCascadeCleanup.server.ts`, the split
read gate, and route/unblock catalogs.
- **Store/engine wiring** (`app/v3/runStore.server.ts`,
`runEngine.server.ts`, `runEngineHandlers.server.ts` + new
`runEngineHandlersShared.server.ts`): points the webapp's store/engine
construction at the resolver, and factors shared handler logic out so
both seams use one path.
- **Read-path touch-ups**: `runtimeEnvironment.server.ts`,
`eventRepository/index.server.ts`, `taskRunHeartbeatFailed.server.ts`,
`engineVersion.server.ts` route their run/environment lookups
read-through the resolver.
- `413a94511` — interlocks split mode against the native realtime
backend so the two aren't enabled in an incompatible combination (see
`.server-changes/run-ops-split-realtime-interlock.md`).
- `dc74c57fd` — drops the earlier "known-migrated" read layer; residency
is determined by id-shape only.
## Why
PR5 of the run-ops split stack. This is the webapp foundation layer: it
stands up the DB topology, flags, and resolver/cache the rest of the
stack depends on, and repoints webapp read paths through the resolver.
Additive when the split is not enabled (existing single-DB behavior
preserved behind flags); behavior-changing on the read-through paths and
the realtime interlock.
## Tests
New vitest coverage across `apps/webapp/test/` and colocated
`*.server.test.ts` files: db topology, split mode, split read gate,
cross-seam guard, mint cutover / flip latency, control-plane cache,
control-plane resolver, distinct-db sentinel, read-through loaders
(route loaders, run-detail loaders, `findEnvironmentFromRun`), and the
run-engine handlers. Testcontainers-backed; no mocks. `pnpm-lock.yaml`
synced for the two new webapp deps.
## Notes
Draft, **stacked on #4116** (`runops/pr04-store-engine`). Review that
first; this diff is against it.
Server-change / changeset note to be added at stack-assembly time.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Daniel Sutton