designer-skill-mcp v0.21.0

designer-skill-mcp v0.21.0

BREAKING: .designer-skill config files with a legacy hook section are now rejected (CONFIG_INVALID); rename hook to detector. Scans: when git fails inside a work tree (timeout, output cap, safe.directory), the filesystem fallback now reports why in coverage.gitListingError and the gate summary (.gitignore not applied). Roots: client roots that do not resolve to a local path are named in the SCOPE_VIOLATION (details.unusableRoots); an invalid roots list is SCOPE_VIOLATION instead of a raw SDK error. Tools: every tool returns thrown errors in the standard failure JSON shape. Interactive HTTP runs say why an update check failed. Tests are now type-checked in CI and release.