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

tools/chemenu/commands/types_cmd.py

@@ -17,6 +17,7 @@ import json
 
 import typer
 
+from chemenu import toc
 from chemenu.commands._util import fail
 from chemenu.types_core import UnknownType, describe_type, list_types
 
@@ -88,4 +89,9 @@ def describe_type_command(
         typer.echo("")
 
     typer.echo("## Authoring guidance")
-    typer.echo(described["body"])
+    # A type-spec over 100 lines carries a generated table-of-contents region
+    # (`chemenu/toc.py`), which serves whoever opens the file. Here it would be
+    # noise: this command already hands over the whole body, so there is
+    # nothing left for a navigation aid to navigate - only markers and a list
+    # of headings the reader is about to see anyway.
+    typer.echo(toc.strip_region(described["body"]))

tools/chemenu/commands/version_cmd.py

@@ -204,7 +204,7 @@ def bump_command(
     breaking: Optional[str] = typer.Option(
         None,
         "--breaking",
-        help="What stops working, for the bump that first escalates to a boundary crossing (recorded in CHANGES.md). Required there, refused on a bump that crosses nothing",
+        help="What stops working (recorded in CHANGES.md). Required on the bump that first escalates to a boundary crossing, optional on a later bump of the same crossing candidate - where it joins the reasons already recorded rather than replacing them. Refused on a bump that crosses nothing",
     ),
     no_migration: Optional[str] = typer.Option(
         None,
@@ -241,9 +241,16 @@ def bump_command(
     version is not a drop-in replacement, whether or not any content moves -
     requires `--breaking "<what stops working>"`, and on top of that either a
     migration document for the new base or `--no-migration "<reason>"`. Both
-    lines are written into the entry once and then persist across every later
-    bump at the same stage: a follow-up bump need not repeat them, and passing
-    either on a bump that crosses nothing at all is refused.
+    are written into the entry and persist across every later bump at the same
+    stage, so a follow-up bump need not repeat them, and passing either on a
+    bump that crosses nothing at all is refused.
+
+    A candidate can cross the boundary more than once, and the two flags part
+    ways there. A further `--breaking` **joins** the reasons already recorded -
+    each crossing is its own thing an operator has to act on, and replacing
+    meant the second one silently deleted the first. A further
+    `--no-migration` **replaces**: whether content has to change is one
+    question about the candidate as a whole, not one per crossing.
 
     A later bump of the same candidate that finds out `--no-migration` was
     wrong after all retracts it with `--migration-required` - write the