The reference link definitions at the end of PLAN.md included multiline
titles and query strings, which caused Prettier to wrap them across multiple
lines without angle brackets and rumdl (MD034) to flag the indented URLs and
re-add angle brackets. This created an alternating conflict on every `just fmt`
invocation.
Simplify the link reference definitions to single-line URLs without query
strings and titles so both Prettier and rumdl format cleanly and idempotently.
Test Plan:
- `just fmt` -- formatted cleanly with no changes across repeated runs
- `just clippy` -- passed
- `just test` -- all 118 unit tests passed
ddidderr