gofmt -w across the controller tree (46 files) so gofmt -l is empty — disarms the
formatting landmine where a targeted edit + accidental gofmt -w swept ~46 unrelated
files. Pure formatting: whitespace + gofmt's optional-semicolon removal in reflowed
inline closures. One doc comment reworded ('' -> 'the empty string') to avoid gofmt's
Go-1.19 doc-comment typographic substitition ('' -> curly quote) muddying its meaning.
No build/vet/test behavior change.
Belt (ensureUserdataMounts) + FileBrowser sync skip ensure/mount when an external
drive root is not a live mountpoint -> no 'mkdir userdata: permission denied' + no
rootfs-shadow during a drive-absent window. System/local path never gated. Reuses
system.IsMountPoint; matches planDriveGates external-only rule. T1-T4 + red-proofs.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>