docs: tools/CONTRACT.md als Nachschlage-Dokument strukturiert, AGENTS.md-Routing angepasst (schliesst #92)

Files changed:
- AGENTS.md
- CHANGES.md
- VERSION
- tools/CONTRACT.md
- tools/chemenu/tests/test_docs_verify.py

AGENTS.md

@@ -183,7 +183,7 @@ stack is built the way it is - see [File naming](#file-naming)), and this file.
 | `kb/` | [kb/CONTRACT.md](kb/CONTRACT.md) + `kb/CONVENTIONS.md` | What the stack enforces about a page (collections, linking, provenance), and beside it what this instance decided (language, naming, tone, labels, hedging) |
 | `reports/` | [reports/CONTRACT.md](reports/CONTRACT.md) | Why reports and traces are generated, gitignored, and carried into `kb/log.md` |
 | `work/` | [work/CONTRACT.md](work/CONTRACT.md) | Workshop runs: run keys, required files, why they are tracked, how a run closes |
-| `tools/` | [tools/CONTRACT.md](tools/CONTRACT.md) | Full command reference, per-command error contracts, maintenance schedule |
+| `tools/` | [tools/CONTRACT.md](tools/CONTRACT.md) | Command reference and per-command error contracts, one row per command in each of two tables - a file to look a row up in rather than read through, as its own opening paragraph says - plus the maintenance schedule |
 | `instructions/` | [instructions/CONTRACT.md](instructions/CONTRACT.md) | Instruction vs. skill, publishing, writing standard |
 
 **By collection** - then read the contract for the collection you are writing in.