stack-dev/stack-close skill split; publish stack-machinery note; model-selection fix (#47 Block 2)

Files changed:
- CHANGES.md
- VERSION
- instructions/claude-code-model-selection.md
- instructions/dev/stack-close/SKILL.md
- instructions/dev/stack-dev/SKILL.md
- tools/CONTRACT.md
- tools/chemenu/commands/git_publish.py
- tools/chemenu/tests/test_git_publish.py

instructions/dev/stack-dev/SKILL.md

@@ -46,9 +46,10 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    package, labelled `area/`, `kind/`, `prio/` and `size/`. There is no `TODO.md`. **The body
    of the issue you are working on is this session's plan file:** keep it current as the state
    moves, so an interrupted session leaves a body the next one can resume from, *and* rewrite it
-   to its final state before closing. Both halves bind; the second is step 6 below. Read it
-   before filing something for later, before editing or closing an issue, or before deciding
-   what to pick up next.
+   to its final state before closing. Both halves bind; the second is what
+   [`stack-close`](../stack-close/SKILL.md) carries out once this skill's own work is published -
+   see step 5 below. Read it before filing something for later, before editing or closing an
+   issue, or before deciding what to pick up next.
    [testing-conventions.md](../testing-conventions.md) - the suite runs against a deliberately
    empty machine; what the autouse fixture already neutralizes, and what a test still has to
    establish itself. Read it before adding or changing a test.
@@ -63,14 +64,18 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    list grows without needing this skill file to change shape.
 3. **Settle the design before building - and break there for the model switch.** These are two
    different kinds of work, and the split is not stylistic: design, the version part and any
-   boundary judgment have **no** mechanical guard, while the code and tests that follow have
-   `pytest`, `docs verify`, `instructions verify` and CI behind them.
+   boundary judgment have **no** mechanical guard, while the code and tests that follow are mostly
+   covered - `pytest`, `docs verify`, `instructions verify` and CI catch a mistake **in what they
+   cover**.
 
    So when the design is settled - the issue body says what will be built, the open questions are
-   answered - stop and say so, in one sentence:
+   answered - stop and say so, in one sentence that names what the mechanical stretch does **not**
+   cover:
 
-   > Der Plan steht, ab hier ist die Arbeit mechanisch und durch Tests/CI abgedeckt. Wenn du auf
-   > Opus bist, ist jetzt der Moment für `/model sonnet` bei Effort `high`.
+   > Der Plan steht, ab hier ist die Arbeit größtenteils mechanisch und durch Tests/CI abgedeckt -
+   > mit Ausnahme der Changelog-Prosa (Schritt 4), einer berührten `docs/`-Seite, neuer
+   > Menschendoku oder des Prosa-Anteils einer Instruction. Wenn du auf Opus bist, ist jetzt der
+   > Moment für `/model sonnet` bei Effort `high`.
 
    **You cannot make this switch yourself** - the session's model is the user's `/model`, not a
    setting an agent applies. Offer it once and keep working either way; a session that argues
@@ -78,6 +83,15 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    be settled after all - a boundary crossing surfaces, an assumption breaks - that is a reason to
    offer the switch back up, not to decide it alone.
 
+   **"Covered by tests" means covered by the tests that exist, not by the tests that should
+   exist.** Whether the right test was written is itself a judgment call with no mechanical
+   guard: two data-destroying bugs in `upstream merge` (Gitea #30) shipped past a green
+   `pytest`/`docs verify`/`instructions verify`/CI because no test exercised the case, not
+   because a weaker model wrote worse code for the case that *was* tested. This is not a third
+   break - it is a caveat on this one: the middle phase stays the cheaper phase to run on, but its
+   test suite is only as complete as the judgment that wrote it, and that judgment is unchecked
+   the same way the design phase is.
+
    Effort is the cheaper lever than the model, and `high` is the floor for anything touching more
    than one file or a contract. Full table and reasoning:
    [claude-code-model-selection.md](../../claude-code-model-selection.md).
@@ -119,47 +133,23 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    Prose-only changes (`README.md`, `INSTALL.md`, `EVALS.md`) and the workflows under `.gitea/`
    do not need a bump - CI's version gate is scoped to what changes behaviour.
 
-5. **Verify before publishing.** `tools/wikitool docs verify`, `tools/wikitool instructions
-   verify`, and the relevant `pytest` run in `tools/` - the same checks any stack change must
-   pass, run explicitly rather than assumed. CI (`.gitea/workflows/ci.yml`) runs these plus a
-   full `setup-instance.md` replay against a fresh `dist export`; a push to `main` that moves
-   `VERSION` additionally triggers a tagged release. **CI does the tagging** - a session never
-   creates a tag, which is what keeps AGENTS.md invariant 5 intact.
+5. **Verify, then publish.** `tools/wikitool docs verify`, `tools/wikitool instructions verify`,
+   and the relevant `pytest` run in `tools/` - the same checks any stack change must pass, run
+   explicitly rather than assumed. CI (`.gitea/workflows/ci.yml`) runs these plus a full
+   `setup-instance.md` replay against a fresh `dist export`; a push to `main` that moves `VERSION`
+   additionally triggers a tagged release. **CI does the tagging** - a session never creates a
+   tag, which is what keeps AGENTS.md invariant 5 intact.
 
-6. **Close the issue with a body rewrite, not a comment.** The last act of a session that
-   finished a work package, and the one most easily skipped: by here the change is published and
-   the issue feels done. It is not. The body is the version everyone reads afterwards and nobody
-   revisits, so it is the one place the debt comes due at the worst moment.
+   Publish with `tools/wikitool publish`. When the changeset touches `tools/`, `types/`,
+   `instructions/`, `AGENTS.md` or a `<stage>/CONTRACT.md`, `publish` itself prints a one-line
+   reminder that the phase past this point is not covered by any of the checks above - that line
+   is the cue that this skill's own job just ended.
 
-   **Break here too, in the other direction.** Everything left in the session - this rewrite,
-   whether a `docs/` page's reasoning went stale, the changelog prose - is the unchecked kind of
-   work again, the mirror of step 3. If the session dropped to Sonnet there, say so now:
-
-   > Ab hier greift kein maschineller Check mehr - Issue-Body, `docs/`-Veralterung und
-   > Changelog-Prosa prüft nichts. Wenn du zurück auf Opus willst, ist jetzt der Moment.
-
-   Then **do the work regardless of the answer.** Never block a close on a model switch: the
-   change is already published, and a session that stops here leaves exactly the state this step
-   exists to prevent. If it ran on the cheaper model, name that in the handover rather than
-   leaving it silent.
-
-   Rewrite it to its final state *first*, then close. The test is what a reader who opens the
-   closed issue tomorrow would conclude:
-
-   - every acceptance criterion ticked, or struck with the reason it was dropped
-   - proposals that were decided read as decided; a "to decide" section has become the decision
-     and its reasoning
-   - nothing left in the present tense about a defect that no longer exists
-   - what was verified is named - which checks ran, which CI run - not a commit hash alone
-
-   Then one short comment naming what changed against the previous state, and nothing else.
-
-   **A closing report in a comment does not satisfy this**, however thorough: it reads as
-   complete to whoever writes it and leaves a body still phrased as open work. Nothing
-   mechanical catches it - `wikitool` does not know this tracker exists and must not learn it,
-   since it ships to instances that have no board - so this step is the only enforcement there
-   is. #44 and #45 both closed exactly this way, the second an hour after the rule was written.
-   [issue-tracking.md](../issue-tracking.md) step 7 has the full shape.
+   **This skill stops here.** The closing phase - rewriting the issue body to its final state,
+   checking for `docs/` staleness, and naming which model ran which phase of the session - lives
+   in [`stack-close`](../stack-close/SKILL.md), not in a further step of this one. Invoke it now;
+   do not fold its work into this session under this skill's rules, and do not treat "the change
+   is published" as this work package being done.
 
 ## Decision points
 
@@ -180,4 +170,5 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
 
 Not for wiki content work - use `wiki-ingest`/`wiki-query`/`wiki-manage`/`wiki-lint`/
 `wiki-status` for that. Not for setting up a new instance (`instructions/setup-instance.md`) or
-a fresh clone of this repo (`instructions/bootstrap.md`).
+a fresh clone of this repo (`instructions/bootstrap.md`). Not for closing a work package after
+its publish has landed - that is [`stack-close`](../stack-close/SKILL.md).