stack: TOC-Scope auf types/ und docs/, Sprachregeln nach AGENTS.md zentralisiert, alle Templates auf Control-Plane-Sprache, --breaking akkumuliert (schliesst #99)

Files changed:
- AGENTS.md
- CHANGES.md
- ENVIRONMENT.md.template
- SOUL.md
- SOUL.md.template
- USER.md.template
- VERSION
- docs/ownership-and-templates.md
- docs/version-model.md
- instructions/CONTRACT.md
- instructions/dev/doc-pull-through.md
- instructions/dev/stack-close/SKILL.md
- instructions/dev/stack-dev/SKILL.md
- instructions/dev/version-parts.md
- instructions/setup-instance.md
- kb/CONVENTIONS.md
- kb/CONVENTIONS.md.template
- kb/concepts/COLLECTION.md
- kb/sources/COLLECTION.md
- tools/CONTRACT.md
- tools/chemenu/commands/types_cmd.py
- tools/chemenu/commands/version_cmd.py
- tools/chemenu/tests/test_toc.py
- tools/chemenu/tests/test_version_cmd.py
- tools/chemenu/toc.py
- tools/chemenu/version.py
- types/comparison.md
- types/concept.md
- types/entity.md
- types/lint-report.md
- types/source.md

instructions/dev/doc-pull-through.md

@@ -40,7 +40,24 @@ touched; a row that does not apply needs no action.
    | The reasoning behind a gate, boundary, or design decision | The `docs/` page that carries it, if one exists (AGENTS.md § File naming lists all four) |
    | A skill's own step sequence or catalogue | The skill's `SKILL.md` source under `instructions/<name>/` or `instructions/dev/<name>/` |
 
-3. **Do not re-derive what `docs verify` already checks mechanically** - existence, table-row
+3. **A heading you changed means a table of contents to regenerate - by the tool, never by
+   hand.** Every reference file over 100 lines carries one (`AGENTS.md`, the stage contracts,
+   `kb/CONVENTIONS.md`, each `COLLECTION.md`, the flat `instructions/**.md` form, the
+   type-specs, the `docs/` pages - a `SKILL.md` is the one exception). Adding, renaming,
+   reordering or deleting a `##`/`###` heading in one of them makes its region stale, and
+   `docs verify` fails on stale exactly as it fails on missing:
+
+   ```bash
+   tools/wikitool docs toc          # dry run: which files would change
+   tools/wikitool docs toc --apply  # write them
+   ```
+
+   The region is generated, so AGENTS.md invariant 1 applies to it like any other: editing the
+   list by hand is the failure, not the fix - and a hand-written entry survives until the next
+   `--apply` silently disagrees with it. It is cheap to over-run: `--apply` is idempotent and a
+   file whose headings did not move is left untouched.
+
+4. **Do not re-derive what `docs verify` already checks mechanically** - existence, table-row
    membership, ignore-canary state. That enumeration lives once, in
    [tools/CONTRACT.md](../../tools/CONTRACT.md)'s own `docs verify` row; copying it here would be a
    second copy that drifts, the exact failure this instruction exists to describe (Gitea #90).

instructions/dev/stack-close/SKILL.md

@@ -48,10 +48,12 @@ and a fresh subagent starts without the session's context).
 
 ## Steps
 
-1. **Offer the model switch back up, once, and keep working either way.**
+1. **Offer the model switch back up, once, and keep working either way.** A model of the
+   message, not a script to quote: say it in the instance's KB language, per `AGENTS.md`
+   § File naming.
 
-   > 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.
+   > From here on no mechanical check applies - nothing verifies the issue body, `docs/`
+   > staleness, or the changelog prose. If you want to switch back to Opus, now is the moment.
 
    **Never block on the answer.** The change is already published; a session that stops here
    leaves exactly the state this skill exists to prevent.
@@ -86,6 +88,11 @@ and a fresh subagent starts without the session's context).
    behaviour one of these documents describes, update it now; if none did, say so rather than
    leaving the question unasked.
 
+   **If that update moved a `##`/`###` heading, the file's table of contents is now stale** -
+   regenerate it with `tools/wikitool docs toc --apply`, never by editing the list. The region
+   is generated (AGENTS.md invariant 1), `docs verify` fails on stale exactly as on missing, and
+   a pull-through in this phase is a common way to move a heading without noticing.
+
    **A pull-through of its own needs its own bump.** This phase runs *after* `stack-dev` step 4
    has already bumped the version, and the documents it touches are frequently the ones CI's
    version gate watches - `types/`, `instructions/`, `tools/`, `AGENTS.md`, any

instructions/dev/stack-dev/SKILL.md

@@ -76,12 +76,13 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
 
    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 that names what the mechanical stretch does **not**
-   cover:
+   cover. The message below is a model of what to say, not a script to quote: say it in the
+   instance's KB language, per `AGENTS.md` § File naming.
 
-   > 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`.
+   > The plan is settled. From here the work is mostly mechanical and covered by tests/CI -
+   > except the changelog prose (step 4), any `docs/` page you touch, new human-facing
+   > documentation, and the prose half of an instruction. If you are on Opus, now is the moment
+   > for `/model sonnet` at 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
@@ -146,7 +147,13 @@ stack development happens in the origin repo instead (see AGENTS.md's routing li
 
 5. **Pull through every document that makes a claim about the surface you touched - `docs verify`
    checks a cell's presence, never its prose.** `instructions/dev/doc-pull-through.md` has
-   the table of which document that is, per surface.
+   the table of which document that is, per surface, and its step 3 for the one part of the
+   pull-through that is *not* prose: a reference file whose headings moved needs
+   `tools/wikitool docs toc --apply`, never a hand-written list.
+
+   Prose you write here is English, whatever language the session is being held in -
+   `AGENTS.md` § File naming has both language rules and the line between prose and quoted
+   vocabulary.
 
 6. **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

instructions/dev/version-parts.md

@@ -66,7 +66,12 @@ a new one, and only `version release` turns it into something the release workfl
 
   1. **Heading, author, breaking/migration lines** - written by `version bump`, anchored right
      above the bump list so the line an operator most needs to act on never sits beneath a list
-     that can run long.
+     that can run long. The breaking line **accumulates** across a candidate's crossings - one
+     reason on the marker line, bullets under a bare marker from the second onward - because a
+     long-running candidate can break compatibility more than once and each break is its own
+     thing to act on. The migration line does not: it answers one yes/no about the candidate as
+     a whole, and `--migration-required` is its retraction path. Nothing retracts a breaking
+     reason; a wrong one is rare enough, and the candidate is dev-local until release.
   2. **The bump list**, grouped `**High/Medium/Low impact**` (empty groups omitted) - rendered by
      `version bump`'s `--impact` (default `medium`), corrected after the fact by `version regrade`.
      Flat and ungrouped, exactly as before this layering existed, when every bump is `medium` - the