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).