Create the browser smoke page under GITHUB_WORKSPACE so the runtime's local-file trust boundary permits it on every runner, and advance the immutable bootstrap channel to RC3.
Use an allowed local file URL for the browser smoke test, centralize keyless archive signing after native builds so Windows ARM64 does not require an unavailable Cosign binary, and advance the immutable bootstrap channel to RC2.
Publish signed prerelease artifacts from v2.0.0-rc.* tags, bind bootstrap trust to the immutable RC tag, make missing-release errors actionable, and install the six public skills from the canonical subpath.
Detect host-native browser tools before offering the isolated local Chromium fallback, add a common readiness fixture, harden managed browser startup, and verify standards installs expose one canonical QA skill.
Sinabina