* fix(gsd): write DB before disk in validate-milestone to match engine pattern
validate-milestone.ts wrote the VALIDATION.md file to disk before
inserting the assessment row into the DB. Every other handler in the
engine (complete-task, complete-slice) does DB-first, disk-second with
rollback compensation. The inverted order meant a crash between disk
write and DB insert would leave an orphaned file with no DB record —
a state that is harder to detect and recover from than the inverse
(DB row exists, file missing → projection rendering can regenerate).
Fix: reorder to DB-first, disk-second. On disk write failure, delete
the DB row via DELETE FROM assessments so state stays consistent.
Add two handler-level tests verifying:
1. Both DB row and disk file exist after success
2. DB row is rolled back (deleted) when disk write fails
Closes#2725
* fix(test): use file-as-directory to trigger disk failure cross-platform
chmod 0o444 does not prevent writes on Windows. Replace with
replacing the milestone directory with a regular file, so
saveFile's mkdirSync/write fails on all platforms.
Fixes windows-portability CI failure.
6172246772