feat: retire /investigate after a no-gain eval (GST-1717) (#4110)

* feat: retire /investigate after a no-gain eval (GST-1717)

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

* fix(skill-start): core routing offer drops every non-core rule line (GST-1717)

The retired /investigate rule became 'Bugs/errors → fix them directly', which no
longer matches '→ invoke /', so proactive=core leaked it into the offered section.
Match any '- … → ' rule line.

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

* revert(review): keep review/checklist.md at its no-loss-pinned bytes (GST-1717)

The pin names replay GSTA-224 H1; a reviewer checklist edit merges only after a
passing no-loss replay (crew rule 15). The /investigate flake line stays until a
replayed repin.

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

* test: repair free-suite fallout from retiring /investigate (GST-1717)

CI run 42340956269 at 83a8a9a: drop fixtures, ledger rows, allowlist entries and
counts for the retired skill and its deleted paid files; record the harness
change as non-behavioral; the test-of-test detector accepts path.join(ROOT, 'bin');
uncovered-prompt fixtures use a tracked prompt, since an untracked path now
reads as a deleted one.

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

* fix(relink): back up a retired skill's real SKILL.md before cleaning it (GST-1717)

With the skill's source gone, the customized-file check never ran, so a
banner-carrying local copy of investigate/SKILL.md was deleted instead of moved
to the backup root (red-team review, pass 1).

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

* fix(qm): restore the review checklist's flake-line rewrite (GST-1717)

review/checklist.md keeps its pinned /investigate line, so the QM edition needs
its replaceText rule back; qm/ stays fresh against the generator.

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

* docs(changelog): name the setup flag break, the relink backup and the pinned checklist line (GST-1717)

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

* fix(setup,relink): back up a retired skill's real SKILL.md instead of deleting it (GST-1717)

Scoped fix round under grant a-360dd62bd46a (outside-voice blocking finding and
adversarial #1, #4). setup's prune compares a copied host entry with the render
before removing that render, and backs up a copy that differs or whose render is
gone; relink no longer takes the marker's rm -rf for a skill whose source is
gone, so a real SKILL.md is backed up and the user's files stay. setup reports a
failed remove-source of the retired gate hooks on stderr.

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

* fix(pr-profile): a changed prompt counts as deleted only when it is gone from disk (GST-1717)

An untracked prompt file on disk still needs prompt validation (targeted review
finding); harness change recorded as non-behavioral.

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

* docs(changelog): exact backup wording, the hook-removal warning and GST-1744 (GST-1717)

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

* fix(setup): one backup folder per host for a retired skill's copies (GST-1717)

Under grant a-c95576b8b1f9 (fix-check#1): every copy host moved its
gstack-investigate/SKILL.md to the same backup path, so a later host's copy
overwrote an earlier host's edits. A sandboxed ./setup --host factory run showed
gen-skill-docs removes the retired render before the prune, so every real copy
is backed up; each host now gets its own folder.

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

* docs(changelog): say exactly what setup backs up for a retired skill (GST-1717)

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

* docs(changelog): end the two colon sentences prose-lint flagged (GST-1717)

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

* test(retired-skills): name plan-eng-review once behind a pregate-literal waiver (GST-1717)

pregate's literals check read the GSTACK_RETIRED_SKILLS change as an old
value still in the tests. plan-eng-review is still retired; investigate was
appended. The fixture names it once, with the waiver.

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>

.github/workflows/windows-smoke.yml

@@ -6,7 +6,7 @@ name: Windows Smoke
 #   1. ./setup --host claude into an isolated HOME under Git Bash, with
 #      gstack's own browser (Playwright Chromium).
 #   2. The core skills start: gstack-skill-start for /ship, /review,
-#      /qa-only, /investigate and /browse answers SKILL_START_PROTO: 1.
+#      /qa-only and /browse answers SKILL_START_PROTO: 1.
 #   3. /browse on gstack's own browser: the installed browse runs a piped
 #      chain flow against a local page from an unrelated directory.
 #   4. The fastest Windows-safe free tests for those paths (list below).
@@ -69,7 +69,7 @@ jobs:
           SMOKE_HOME="$RUNNER_TEMP/smoke-home"
           USERPROFILE="$(cygpath -w "$SMOKE_HOME")"
           export HOME="$SMOKE_HOME" USERPROFILE
-          for skill in ship review qa-only investigate browse; do
+          for skill in ship review qa-only browse; do
             set +e
             OUT=$(timeout 120 "$SMOKE_HOME/.claude/skills/gstack/bin/gstack-skill-start" --skill "$skill" --model claude 2>&1 < /dev/null)
             CODE=$?