feat: Korpus-Kuratierungsrichtlinie - Floors und Leitplanke fuer reaktive Fixes (4.2.0, #28)

Files changed:
- CHANGES.md
- VERSION
- instructions/dev/corpus-policy.md
- instructions/dev/stack-dev/SKILL.md

CHANGES.md

@@ -20,6 +20,44 @@ their date-only headings.
 
 ---
 
+## 4.2.0 - 2026-09-03 - Korpus-Kuratierungsrichtlinie: Untergrenzen und Leitplanke für reaktive Fixes
+
+**Author:** Torben Nehmer
+
+Ein Demo-Korpus will klein und stabil sein, ein Testbett groß, unordentlich und in Bewegung -
+dieses Repo verlangt seit der Veröffentlichung beides vom selben `kb/` (Gitea #28). Die Sitzung
+vom 2026-09-02 hatte Fixture, `--with-demo` und ein zweites Repo bereits verworfen; offen blieb
+nur, wie kuratiert "kuratiert genug" heißt und welche Leitplanke reaktive Fixes bekommen.
+
+**Neu:** `instructions/dev/corpus-policy.md`. Fünf Untergrenzen, jede mit einer bestehenden
+`wikitool`-Prüfung messbar, keine davon durch neuen Tool-Code: jeder Seitentyp und jeder
+deklarierte Subtyp mit mindestens einer Seite, mindestens fünf Seiten mit mindestens drei
+Quellen, ein bis zehn Orphan-Seiten, im Schnitt mindestens vier ausgehende Wikilinks pro Seite.
+Gemessen am 2026-09-03: 181 Seiten, alle Typ-/Subtyp-Floors erfüllt, 12 Seiten mit ≥3 Quellen, 3
+Orphans, Ø 6,2 ausgehende Links - der Korpus war bereits groß genug, ohne dass eine einzige
+Seite eigens dafür angelegt werden musste. Eine Untergrenze wird nie durch eine erfundene Seite
+gefüllt, sondern durch eine echte Quelle beim nächsten passenden Ingest - Invariante 3 gilt
+unverändert.
+
+**Die Leitplanke für reaktive Fixes** unterscheidet drei Stufen: punktuelle Änderungen (immer
+erlaubt, gewöhnliche Arbeit), korpusweite Änderungen (nur geplant, mit eigenem Issue und
+`work/`-Run - trifft eine Session das Mass-Update-Gate während sie etwas anderes tat, holt sie
+sich nicht den `--confirm`-Token, sondern stoppt und legt ein Issue an) und reaktive Eingriffe
+in Korpusinhalt, um einen Test grün zu machen oder einen Tool-Bug zu umgehen (nie erlaubt,
+Invariante 7). Das Verhältnis zu `kb_dir`/`raw_dir` und `test_pipeline_l0.py` bleibt wie im
+ursprünglichen Befund: kleiner, isolierter Fall in der Fixture, großer, vernetzter Fall in
+`kb/` - keine Fixture-Extraktion aus dem Korpus.
+
+Dev-only und rein additiv - kein Feld, kein Kommando, keine Datei außerhalb von
+`instructions/dev/` ändert sich, daher `--minor` ohne `--breaking`.
+
+**Migration:** none required.
+
+Berührt: `instructions/dev/corpus-policy.md` (neu),
+`instructions/dev/stack-dev/SKILL.md` (Schritt 2, Routing-Zeile).
+
+---
+
 ## 4.1.2 - 2026-09-03 - Issue-Abschluss ist ein Body-Rewrite, nicht nur ein Kommentar
 
 **Author:** Torben Nehmer

VERSION

@@ -1 +1 @@
-4.1.2
+4.2.0

instructions/dev/corpus-policy.md

@@ -0,0 +1,94 @@
+---
+type: types/instruction.md
+name: corpus-policy
+description: What "curated enough" means for kb/ when it is demo and testbed at once, the measurable floors that define it, and what a reactive fix to the corpus may and may not do.
+---
+# Keep kb/ curated enough to develop against, without a second corpus
+
+This instance runs one `kb/` for two purposes at once: a public demo and the testbed this stack
+is developed against. There is deliberately no fixture corpus, no `--with-demo` export, and no
+second repository - see Gitea #28. The corpus's size and shape are set by what targeted
+development needs, not by a synthetic fixture size or a demo aesthetic.
+
+## When to run
+
+- Before judging whether the corpus can exercise a change under development - ranking, index
+  scaling, orphan detection, a new label, a new type-spec.
+- Before a reactive fix touches `kb/` content rather than the failing code - the floors below
+  are what decides whether the fix may proceed as-is.
+- Picking up Gitea #28 or #30, or any issue that references this file.
+
+## The floors
+
+Each is mechanically checkable with an existing `wikitool` command; none needs new tool code.
+A floor exists to keep some class of bug observable, not to describe an aesthetic target - so
+when a session is about to make one of these numbers *worse*, that is the signal to stop and
+think, not a number to defend for its own sake.
+
+| Floor | Check | Why this number |
+|---|---|---|
+| Every page type has ≥1 page | `wikitool search --field type=types/<t>.md` | A type with zero pages means its schema, its collection contract and its lint rules are unexercised |
+| Every declared subtype has ≥1 page | `wikitool search --field <x>_type=<v>` | Same reasoning, one level down - `entity_type`, `concept_type`, `source_type` |
+| ≥5 pages corpus-wide with ≥3 `sources:` entries | one-off script, see below | Provenance fan-in - multiple sources backing one claim - is a real case only a handful of pages exercise; fewer than 5 and a provenance-index bug can hide |
+| Orphan pages (no inbound link) between 1 and 10 | `wikitool lint` | Zero orphans makes orphan detection itself unobservable; more than 10 means the corpus stopped being curated |
+| Average outbound wikilinks per page ≥4 | one-off script, see below | Below this, ranking and graph-traversal work has too little structure to exercise |
+
+A floor is a lower bound only. There is no upper bound on page count or on any of these numbers
+except the orphan ceiling above - a corpus that outgrows these floors through real ingests is
+not a problem this file cares about.
+
+**Measured 2026-09-03** (see Gitea #28): 181 pages, 14/14 types and subtypes covered, 12 pages
+with ≥3 sources, 3 orphans, 6.2 average outbound links. All floors held without any manufactured
+content - the corpus was already big enough when the question was asked.
+
+A type or subtype sitting at exactly the floor - one page - shows no set-level bugs, only that
+the type is *reachable*. That is a soft target for the next `wiki-ingest` that happens to
+produce a matching page, never a reason to write one: filing an unsourced page to clear a floor
+is exactly what AGENTS.md invariant 3 forbids, floor or no floor. The same holds for an
+authorised link label with zero live uses (`wikitool xref` reports these) - fill it when a real
+edge calls for it, never manufacture one to exercise the label.
+
+To check the two floors without a dedicated command, walk `kb/**/*.md` (excluding
+`INDEX.md`/`COLLECTION.md`/`CONTRACT.md`/`CONVENTIONS.md`), parse frontmatter, and: count pages
+whose `related:` array (resolved against page titles) has ≥3 entries for outbound density; count
+`sources:` array length ≥3 for the provenance floor. `wikitool search` and `wikitool lint`
+cover everything else in the table.
+
+## What a reactive fix may do to kb/ content
+
+Three tiers, by how much of the corpus a change touches:
+
+1. **Pointwise - always allowed.** Creating, updating, renaming or deleting a single page
+   through the normal tools (`new`, `touch`, the page-lifecycle procedure), below the
+   Mass-Update Gate's threshold. This is ordinary work and needs no special permission.
+2. **Corpus-wide - planned only, never reactive.** A migration, a vocabulary sweep, a bulk
+   `touch` across many pages. This needs its own issue and, per `work/CONTRACT.md`, a `work/`
+   run - never a same-session reaction to whatever the session was originally doing. If a
+   session hits the Mass-Update Gate (exit 42, see `instructions/gates.md`) while working on
+   something else, it does not fetch the `--confirm` token to push through: it stops, opens an
+   issue for the corpus-wide change, and finishes the original task without it.
+3. **Reactive - never allowed.** Deleting or reshaping a page to make a failing test pass;
+   restructuring corpus content to route around a tool bug (AGENTS.md invariant 7); using
+   `kb/` as a scratch surface for a tool experiment. If a stack change under development needs a
+   corpus shape that does not exist, build it as a pytest fixture (see the next section) -
+   never manufacture it in `kb/`.
+
+## Relationship to the test fixtures
+
+`tools/chemenu/tests/conftest.py`'s `kb_dir`/`raw_dir` fixtures and `test_pipeline_l0.py` cover
+the **small, isolated** case: a handful of pages, built fresh per test, hermetic. `kb/` covers
+the **large, connected** case: 181+ pages, grown link density, real provenance history that no
+per-test fixture reconstructs economically. The cut: if a `tmp_path` tree can reproduce what the
+test needs, it belongs in a fixture; if the test needs density or scale that only a grown corpus
+has, it belongs against `kb/`. Neither absorbs the other's job - see
+[testing-conventions.md](testing-conventions.md).
+
+## Decision points
+
+- **A floor would be violated by an in-progress change - is that a blocker?** Only for the
+  orphan ceiling and the type/subtype floors, since those two can go to zero. The density and
+  provenance floors move gradually with ordinary ingests and are not gating on any single
+  session.
+- **Corpus is "too small" for a feature under development?** That is not this file's problem to
+  solve by adding pages - see tier 3 above. Either the feature waits for a real ingest to supply
+  the shape, or it gets a pytest fixture.

instructions/dev/stack-dev/SKILL.md

@@ -54,6 +54,10 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
    [version-parts.md](../version-parts.md) - which part a change bumps: the drop-in test, the
    catalogue of breaks that cross the compatibility boundary with `kb/` untouched, and what to
    put in front of the user before a breaking bump. Read it before step 3.
+   [corpus-policy.md](../corpus-policy.md) - what "curated enough" means for the shared
+   demo/testbed `kb/`, the measurable floors that define it, and what a reactive fix may and may
+   not do to corpus content. Read it before judging whether the corpus can exercise a change, or
+   before any fix that would touch `kb/` content.
    More instructions are added here incrementally as stack-development needs come up - this
    list grows without needing this skill file to change shape.
 3. **Raise the version, if the change ships.** A change under `tools/`, `types/`,