JSON.parse, JSONC parse, and native Claude Code keep the last duplicate
object member, and parseClientConfiguration therefore validates the last
one. The shared setup/uninstall serializer instead edited text through
jsonc-parser's modify and findNodeAtLocation, which select the first
matching member, so setup and uninstall on configurations with repeated
server tables or rea members wrote into a shadowed member and failed
readback.
Locate every JSON text edit by the effective (last) member in one place,
replacing the first-member modify path. Removing an effective member
that shadows an earlier duplicate would activate that duplicate, whatever
its ownership, so the serializer now returns a tagged shadowed_member
failure and setup and uninstall refuse before writing a backup or the
configuration.
Fixes#4952
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
