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>
Reuse the writer's monotonic statement index to find the last physical line
of an assignment. Remove the full line-start scan performed for every key.
Preserve source edits, multiline values, BOM, CRLF and final-line handling.
Add LF/CRLF controls with adjacent assignments, multiline values, an empty
value and EOF without a newline. Validated 85 focused tests across six files,
check:fast, docs:check and discovery of all 1553 test files.
Twelve bounded public CLI uninstall tasks preserve equivalent replies,
configuration and original backups. Warm 10000-assignment elapsed medians
were 0.538/0.520 s and CPU 0.817/0.744 s before/after; small-input timings
were noisy and slower in the candidate. No general speedup, cold-cache,
real-client or analysis-provider claim. Heavy profiling remains stopped.
Fixes#4873
