QM edition no longer ships the review skill (GST-2306) (#4279)

* Drop the review skill from the QM edition

A benchmark of the QM edition found gstack-review flagged too many problems
without making the reviewed work better, so the edition now ships only
gstack-plan. Regenerated qm/ and removed the review-only first-step script.

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

* Regenerate the QM edition without the review skill and update its docs and tests

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

* Give the deleted QM review script an empty test lane so the pre-merge check accepts its removal

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

* Point the deleted QM review script at the QM edition test instead of no test lane

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

---------

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

.gstack/pregate.json

@@ -14,7 +14,8 @@
     "LICENSE": [],
     "licenses/**": [],
     "contrib/**": [],
-    "supabase/**": []
+    "supabase/**": [],
+    "qm/sandbox/skills/gstack-review/scripts/diff-base.sh": ["test/qm-edition.test.ts"]
   },
   "selection": {
     "free-tests.yml/free-suite": "bun run scripts/test-free-shards.ts --list"