Adds the Studio (browser) binding so a canary can span the CLI and the editor,
and fixes a bundling mistake the studio test suite caught.
## The binding
Same public API as the CLI — `isCanaryEnabled("name")` — so a call site reads
identically whether it runs in Node or the browser. Three inputs differ:
- UNIT ID: `resolveStudioDistinctId()`, which already adopts
`window.__HF_CLI_DISTINCT_ID` when the CLI launched Studio. A CLI-launched
Studio therefore lands in the SAME cohort as the CLI: a rollout spanning
render and editor is coherent for that user instead of enrolling their
terminal but not their editor. A test pins that the id is passed through
unmodified — prefixing or re-hashing it would silently break that parity.
- OVERRIDE: no `process.env` in a page, so `?hf_canary_<name>=on` mirrored
into sessionStorage. Session scope is deliberate. A URL is the right carrier
(shareable — "support: open this link"), but persisting a URL-borne override
to localStorage would let one click silently pin a browser into a cohort
forever, long after anyone remembers why. Closing the tab is the reset;
`=reset` clears it explicitly.
- EXCLUSION: `navigator.webdriver` stands in for the CLI's `is_ci`. Automated
browsers mint a fresh localStorage id per run, so they would hop cohorts
between runs — noise in the signal, nothing learned about real users. An
override still reaches them, which is how you test a canary under Playwright.
Studio's `trackEvent` now attaches `canaries` to every event, mirroring the CLI.
## The bundling fix
Importing the `@hyperframes/core` barrel into studio browser code broke two
unrelated hook test files with an esbuild TextEncoder invariant violation. The
barrel re-exports the whole core surface (parsers, lint, studio-server), so it
drags a Node-oriented dependency graph into a browser bundle — the test
failure was the symptom, the bundle bloat was the bug.
`@hyperframes/core` now exposes `./canary` and `./canary-registry`, declared in
packages/core/package-subpaths.json (the generated source of truth for exports —
hand-editing package.json is reverted by the sync script) and marked
`environments: [browser, bun, node]`. Both the studio AND cli bindings import
the leaf modules; the CLI gets the same benefit for a different reason, since
this resolves on the startup path — the reason the producer is lazily loaded.
Verified: the two hook files pass again; 269 studio files / 2982 tests, 98
core / 1433, 166 cli / 2194 green, `bun run lint` clean including the subpath
check. Fault-injection confirms both design decisions are pinned — swapping
session for local storage fails the scope test, prefixing the unit id fails the
CLI/Studio cohort-parity test.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Vance Ingalls