* fix(#3130): harden update.md npx invocations against cache-stale and token-routing
Two failure modes with the old form:
1. Cache-stale: npx serves a cached older version (no --package= flag)
2. Token-routing: Bash-tool wrapper misroutes @ token in package@tag spec
All three sibling invocations (local/global/unknown) now use:
npx -y --package=get-shit-done-cc@latest -- get-shit-done-cc $ARGS
--package= forces a fresh registry fetch; -- prevents token misrouting.
Also fixes the manual-update hint in the error-exit block.
Regression test: tests/bug-3130-update-npx-robust-invocation.test.cjs
Suite: 6973/6973 pass. Closes#3130.
* fix(lint): allow-test-rule for update.md structural contract test
