The Windows platform layer disables tool-bash and inserts the pwsh stack, but the shipped presets each mount a tool-bash row that re-enabled the tool on win32 — the session had both a PowerShell-backed bash tool and tool-pwsh, silently, because no spec pinned the composed preset layer.
The Loader now evaluates a disabled: !!js expression against the loader context at every mount decision; disabled is the only interpolated metadata field, and the raw node stays in the options so write-back keeps the !!js form. The standard/code/cordis presets gate tool-bash with process.platform === 'win32', verify-cordis-config allows expressions in disabled only, and the windows-shell spec pins the preset-level invariant.
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