First full run of the expanded Windows lane (13 -> ~258 files, PR #2593
run 31918591602) failed in exactly 8 files. One was a real test bug,
fixed: design-flag-utils embedded a raw Windows ROOT into a bun -e
string where backslashes act as escapes (D:\a\gstack imported as
D:agstack) — forward slashes work on every platform. The other seven
are POSIX-bound in ways the content patterns cannot see (sed/ln/bash
ARE their subject, a shebang shim arrives via variable, wall-clock
retry bounds on the slowest runner) — each gets a receipted
KNOWN_WINDOWS_INCOMPATIBLE entry, and the census pin now covers that
list so a renamed file fails the suite instead of silently keeping a
stale exclusion.