feat: Prosa ist kein Identifier - Link-Taxonomie als Enum, generierte Regionen mit Markern (4.0.0)

Files changed:
- .gitea/workflows/ci.yml
- AGENTS.md
- CHANGES.md
- VERSION
- instructions/CONTRACT.md
- instructions/link-taxonomy.md
- instructions/migrations/4.0.0-link-taxonomy.md
- instructions/setup-instance.md
- kb/CONTRACT.md
- kb/CONVENTIONS.md
- kb/CONVENTIONS.md.template
- kb/comparisons/COLLECTION.md
- kb/concepts/COLLECTION.md
- kb/entities/COLLECTION.md
- kb/sources/COLLECTION.md
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/blocks.py
- tools/chemenu/cli.py
- tools/chemenu/commands/cite_cmd.py
- tools/chemenu/commands/dist_cmd.py
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/links_cmd.py
- tools/chemenu/commands/migrate_cmd.py
- tools/chemenu/commands/new_page.py
- tools/chemenu/commands/page_ops.py
- tools/chemenu/commands/run_budget.py
- tools/chemenu/commands/xref.py
- tools/chemenu/conventions.py
- tools/chemenu/corpus_diff.py
- tools/chemenu/frontmatter_io.py
- tools/chemenu/kb_collections.py
- tools/chemenu/kb_state.py
- tools/chemenu/links.py
- tools/chemenu/lint_core.py
- tools/chemenu/provenance.py
- tools/chemenu/sections.py
- tools/chemenu/tests/conftest.py
- tools/chemenu/tests/test_blocks.py
- tools/chemenu/tests/test_cite_cmd.py
- tools/chemenu/tests/test_conventions.py
- tools/chemenu/tests/test_dist_cmd.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_migrate_cmd.py
- tools/chemenu/tests/test_new_page.py
- tools/chemenu/tests/test_pipeline_l0.py
- tools/chemenu/tests/test_types_cmd.py
- tools/chemenu/tests/test_xref.py
- types/concept.schema.yaml
- types/entity.md
- types/entity.schema.yaml
- types/instruction.schema.yaml
- types/type-spec.md
- work/link-taxonomy-migration/README.md
- work/link-taxonomy-migration/plan.md

types/type-spec.md

@@ -40,6 +40,30 @@ under `kb/`. It is deliberately **not a collection** and carries no `COLLECTION.
 no per-collection type surface, and `tools/wikitool docs verify` fails if a contract appears
 here.
 
+### Who owns a type-spec
+
+`types/` holds two kinds of file, and the line between them is `root:` — already in the
+frontmatter before anyone drew it:
+
+| Type-spec | Describes | Owned by | Ships as |
+|---|---|---|---|
+| `root: kb` (`entity`, `concept`, `source`, `comparison`) | A page **this instance** writes | The instance | `types/<name>.md.template` plus its `.schema.yaml.template`, adopted by a rename |
+| `root: repo` (`instruction`), no `base_dir` (`lint-report`), and `type-spec` itself | A stack artifact | The stack | Verbatim |
+
+A page type-spec's prose, its `## Template` body and its language are therefore the instance's
+to rewrite — an instance writing its pages in another language simply translates the file, and
+an upgrade does not take that back. Improvements to a shipped default reach it as an *offered*
+migration ([instructions/CONTRACT.md](../instructions/CONTRACT.md#instructionsmigrations)),
+never by overwriting.
+
+**What the stack still requires of the type layer is one line.** There must be a type-spec
+declaring `name: source` whose schema requires `raw_files:` — the whole `raw/` → `kb/`
+provenance path (`sources coverage`, `[^cite-id]` resolution, `kb/provenance.md`) asks
+`page.kind == "source"`, so without it nothing resolves. `docs verify` checks exactly that and
+nothing beyond it: not the directory, not the title prefix, not a word of the prose. Which
+collection is stack-required is *derived* from where that type writes rather than listed
+separately, so renaming it stays consistent instead of tripping a hardcoded name.
+
 **Quality goal:** a type-spec is the single source of truth for its type. No structural fact
 about a page type may be restated anywhere else — not in `AGENTS.md`, not in a skill, not in
 Python. Adding a type must require no code change.
@@ -98,11 +122,10 @@ The `## Template` block is filled from the page's own frontmatter, plus `{name}`
 `{entities|table_cells}`. `{field|literal text}` falls back to the literal when the field is
 absent.
 
-Three further variables come from the instance rather than from the page:
-`{section.relationships}`, `{section.see_also}` and `{section.footnotes}`, filled from
-`kb/CONVENTIONS.md`'s `sections:` declaration. A template writes a tool-owned heading through
-one of those and never as literal text - that is what lets an instance change the KB language
-without editing anything under `types/`.
+**A template never contains a tool-owned region.** The links and footnotes regions are generated
+between markers by `xref` and `cite`, rendered from frontmatter, and re-rendered on every write -
+so scaffolding them would create a section an author is forbidden to edit and the tool would
+replace anyway. See `tools/chemenu/blocks.py`.
 
 ### Ownership boundary