Vendor @intx/types, @intx/storage-isogit, and @intx/inference at Interchange head

[TheGreatAxios]

Vendors @intx/types, @intx/storage-isogit, and @intx/inference as source at Interchange upstream head (cd7c5a37747dc39713d1efd24296ea861e6ac82a), replacing the published npm 0.2.2 installs for the first two and re-syncing the already-vendored third.

Why all three together

The staged plan treated @intx/types/@intx/storage-isogit (stage 2) and @intx/inference (stage 3) as separately landable. They are not. The reactor's approval-suspend primitive (upstream 06d39dc6) changes PendingOperation and the BeforeToolDecision return contract across all three packages in one upstream commit — @intx/inference's exported signatures reference types that only exist in the newer @intx/types. Vendoring either side alone does not typecheck by construction, so splitting them across two PRs would require an intermediate broken-build state.

This disproves the plan's §5 claim that "no stage depends on a later one being merged first for main to stay shippable" for this pair. docs/plans/interchange-vendoring-plan.md is corrected in this PR rather than left to mislead the next reader.

Local patches

@intx/types and @intx/storage-isogit are verbatim copies — zero local modifications, so a diff against any later upstream checkout shows 100% upstream-authored lines.

@intx/inference carries local patches. vendor/intx-inference/PATCHES.md is new and records, per file, what each patch fixes and why it is not yet upstream. All 9 previously-carried files were reapplied against the new source; every patch site now carries a one-line Locally patched — see vendor/intx-inference/PATCHES.md#<anchor> marker, so grep -rn "Locally patched" vendor/intx-inference/src enumerates every intentional divergence.

Two patches were dropped as genuinely superseded, verified by reading the new upstream source rather than assuming:

• deliver()'s unhandled-rejection guard — upstream now wraps the whole correlation dispatch in try/catch and routes failures through closeMessageRun, which is stricter than what we carried.
• The reactor-level inference.retry emission — retry moved entirely into harness.ts's runInference wrapper, which emits the event itself; keeping ours would double-emit.

The security- and leak-sensitive patches are all still carried: the correlatingIds unbounded-Set leak on every successful correlated resume, the 16 MiB SSE line cap (OOM vector), and the OpenAI Responses stream-terminal detection (hang).

Consequent migrations in our own source

These are real semantic migrations, not casts to satisfy the type checker:

• inference.thinking.signature → inference.block.signature; upstream generalized signatures from thinking blocks to every signable block kind. Updated the Responses adapters' emission and the perf span classifier.
• ProviderAdapter gained a required parseJSONResponse. The three Responses adapters always request stream: true, so a JSON body reaching them means the response kind was misdetected — they throw ProtocolMismatchError rather than pretend to support a mode never requested.
• ContentBlock gained a safety_rating variant (Gemini promptFeedback content-filter signals); the context-size estimator now counts its blockReason text like every other block kind.
• The vendored (unpatched) OpenAI chat-completions adapter now wraps text as a { type: "text", text } part instead of a bare string when a turn mixes text and images, matching the API's own content-parts contract; the adapter test's expectation was updated to match.

Side effect: arktype duplication resolved

Every published @intx/* package previously carried its own nested arktype install, distinct from the root's — so an instanceof check against a type built by one instance silently returned false against the other. Resolving these packages as workspace members removes the nested installs; bun.lock now shows a single arktype resolution across the tree. Closes CL-5665.

Verification

• bun run typecheck clean
• bun run build clean
• Full suite: 4221 pass / 0 fail across 318 files
• Upstream clone at /Users/thegreataxios/abklabs/interchange was read-only throughout — confirmed clean working tree, HEAD unchanged, zero commits ahead of origin

Reviewed by greybeard (approach) and critique (execution). Critique verified the reapplied tryCorrelate try/finally closes the leak on every exit path, the commitment-boundary retry redesign is coherent, both dropped patches are legitimately superseded, and the src/ migrations are honest fixes rather than stubs.

Docs

docs/VENDORING.md is new: what's vendored, from which commit, patched vs. verbatim, and the re-sync procedure — including the caveat that a vendored package.json's "version": "0.2.2" is a carried-over convention and does not describe the checked-out source. AGENTS.md's Interchange section points at it.

Not in scope: @intx/authz, @intx/agent, @intx/tools-posix, @intx/log remain on published releases.

[linear-code]

CL-5665

CL-5696