`openclaw --version` outputs "OpenClaw 2026.x.y-z" but
readGatewayVersion() passed the full string to Semver.parse(),
which failed on the "OpenClaw " prefix. This caused the app to
fall back to reading package.json from a local source checkout
(~/Projects/openclaw), reporting a false version mismatch.
Strip the product name prefix before parsing so the installed
CLI version is correctly recognized.