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

AGENTS.md

@@ -8,6 +8,22 @@ and is loaded when the task calls for it.
 **Core principle:** never re-derive, always compile. Knowledge is extracted once and
 maintained permanently; anything mechanical is done by `tools/wikitool`, never by hand.
 
+<!-- wikitool:toc -->
+## Contents
+
+- [Bootstrap](#bootstrap)
+- [Invariants](#invariants)
+- [File naming](#file-naming)
+- [Personalization](#personalization)
+- [Environment](#environment)
+- [Routing](#routing)
+- [Gates](#gates)
+- [Tool error contract](#tool-error-contract)
+- [User preferences](#user-preferences)
+- [Developing this stack](#developing-this-stack)
+- [Changelog](#changelog)
+<!-- /wikitool:toc -->
+
 ## Bootstrap
 
 `.agents/skills/` and `.claude/skills/` are generated and **not committed**. If they are