stack: TOC-Pflicht fuer Referenzdateien ueber 100 Zeilen (docs toc); session-setup.md/gates.md nennen die tatsaechliche Budget-Ausnahmeliste (schliesst #73, #76)

Files changed:
- AGENTS.md
- CHANGES.md
- VERSION
- instructions/CONTRACT.md
- instructions/capture-session.md
- instructions/claude-code-model-selection.md
- instructions/dev/issue-tracking.md
- instructions/dev/testing-conventions.md
- instructions/dev/version-parts.md
- instructions/evolve-subtypes.md
- instructions/gates.md
- instructions/german-terminology.md
- instructions/ingest-large-tree.md
- instructions/kb-profiles.md
- instructions/link-taxonomy.md
- instructions/mcp-read-server.md
- instructions/migrate-corpus.md
- instructions/migrations/3.0.0-authoring-conventions.md
- instructions/migrations/4.0.0-link-taxonomy.md
- instructions/private-instance.md
- instructions/session-setup.md
- instructions/setup-instance.md
- kb/CONTRACT.md
- kb/CONVENTIONS.md
- kb/concepts/COLLECTION.md
- raw/CONTRACT.md
- tools/CONTRACT.md
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/commands/instructions_cmd.py
- tools/chemenu/tests/test_docs_verify.py
- tools/chemenu/tests/test_instructions_cmd.py
- tools/chemenu/tests/test_toc.py
- tools/chemenu/toc.py
- types/type-spec.md

instructions/migrations/3.0.0-authoring-conventions.md

@@ -24,6 +24,16 @@ that file rather than from `tools/chemenu/sections.py`.
 `kb/comparisons/` is touched. What changes are the contracts beside them, which is why this is
 `mechanical` and takes minutes rather than a workshop.
 
+<!-- wikitool:toc -->
+## Contents
+
+- [When to run](#when-to-run)
+- [Steps](#steps)
+- [How to tell a migrated instance from an unmigrated one](#how-to-tell-a-migrated-instance-from-an-unmigrated-one)
+- [Decision points](#decision-points)
+- [Scope](#scope)
+<!-- /wikitool:toc -->
+
 ## When to run
 
 After installing 3.0.0 machinery over an instance that was on 2.x, when `tools/wikitool doctor`