fix(ai): build from the committed model catalog instead of refetching it

[snimu]

Problem

packages/ai npm run build was npm run generate-models && tsgo ...: every build (CI Build and check, every Test (*) job, and release build-binaries.yml — all run npm run build) fetched the live model catalog and rewrote src/models.generated.ts in place.

Upstream removed claude-sonnet-4.5 from the catalog sources, but the committed models.generated.ts and 28 in-repo references (including packages/ai tests) still use it. So on every CI run the Build step silently swapped in a catalog without that model, and the subsequent npm run check / Test (ai) failed with e.g.:

packages/ai/test/context-overflow.test.ts(119,46): error TS2345: Argument of type '"claude-sonnet-4.5"' is not assignable to parameter of type '"claude-fable-5" | ...'

Every PR fails Build and check, Test (ai), and build-check-test regardless of content (example: run 33854776241 on #1947).

Fix

Build compiles the committed catalog only:

• packages/ai build is now just tsgo -p tsconfig.build.json.
• npm run generate-models stays as the explicit, reviewed refresh step (it is the existing documented command in AGENTS.md, README, and the generated-file header; no new alias added).

src/models.generated.ts is the generator's only output and is committed (not gitignored), so clean checkouts build and test with no network fetch of the catalog. This PR deliberately does NOT regenerate the catalog — removing claude-sonnet-4.5 references is a separate reviewed refresh.

Callers audited

generate-models had exactly one caller: the packages/ai build script. Root build, prepublishOnly (npm publish), ci.yml (Build and check + all test jobs), and build-binaries.yml (release/beta binaries) all funnel through it, so all now build from the committed catalog. No other workflow, script, or hook invokes generate-models.

Verification (clean checkout in a Prime sandbox, source-only sync + npm ci)

• npm run build: exit 0; models.generated.ts md5 identical before/after; generate-models never invoked.
• npm run check: exit 0 (biome, root tsgo --noEmit, installer check, browser smoke).
• packages/ai npm test: 50 files passed / 22 skipped, 341 tests passed / 720 skipped, 0 failures.

Linear: RES-1269

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Note

Low Risk
Build-script-only change; generate-models remains available for intentional catalog refreshes with no auth or runtime behavior changes.

Overview
Stops implicit model-catalog refresh on every packages/ai build so CI and local builds use the committed models.generated.ts instead of rewriting it from live upstream data.

The build script no longer runs generate-models before tsgo; catalog updates stay on the explicit npm run generate-models step. A changelog note documents that workflow.

^{Reviewed by Cursor Bugbot for commit f6b2059. Bugbot is set up for automated code reviews on this repo. Configure here.}

LOC

Total src: +0/−0 (net +0); tests: +0/−0 (net +0).

Note

Stop refetching model catalog during npm run build in packages/ai

Removes the generate-models step from the packages/ai build script so builds compile against the committed models.generated.ts. Run npm run generate-models explicitly when the catalog needs refreshing.

^{Macroscope summarized f6b2059.}