tools: command records, Links and citations group - one line per cause, examples, prohibitions (#142)

Files changed:
- CHANGES.md
- VERSION
- tools/CONTRACT.md
- tools/chemenu/commands/cite_cmd.py
- tools/chemenu/commands/links_cmd.py
- tools/chemenu/commands/xref.py

CHANGES.md

@@ -59,7 +59,7 @@ concern - readable here, never shipped as something to parse.
 
 ---
 
-## 7.1.0-beta.10 - 2026-09-26 - Command records, Pages group: one line per cause, examples, prohibitions
+## 7.1.0-beta.11 - 2026-09-26 - Command records, Links and citations group: one line per cause, examples, prohibitions
 
 **Author:** Torben Nehmer
 
@@ -79,6 +79,7 @@ concern - readable here, never shipped as something to parse.
 - Command records, Catalog and log group: bullets, examples, prohibitions
 - Command records, Distribution and versioning group: one line per cause, examples, prohibitions
 - Command records, Pages group: one line per cause, examples, prohibitions
+- Command records, Links and citations group: one line per cause, examples, prohibitions
 <!-- /wikitool:bumps -->
 
 ### CalDAV task-tracker provider (Nextcloud Tasks, iOS Reminders); review reports unknown-value findings instead of skipping them
@@ -239,6 +240,16 @@ its page-write failure after the tracker project was confirmed, and the partial-
 42, and behind `task close` taking an id rather than a title, moved into `task_cmd.py`'s module
 docstring.
 
+### Command records, Links and citations group: one line per cause, examples, prohibitions
+
+`xref add`/`remove`/`link-source`, `links show` and `cite id`/`add`/`sync` rewritten the same
+way; text only. `xref add`'s label refusal, previously described only in NOTES, is now an exit
+line of its own, and its exit text says which page's type is checked for `related:` (A's - the
+only one the code looks at). `xref link-source` states that a missing target is skipped while the
+rest are still linked, before the run exits 1, and loses the history of the See Also bullet it
+no longer writes. The two `cite` write commands and `cite id` carry AGENTS.md invariant 1's rule
+on citation ids as NEVER, where an agent looking up one command finds it.
+
 ---
 
 ## 7.0.0 - 2026-09-22 - Task-Tracker-Anbindung: Vorhaben als Seitenart, Verpflichtungsschicht, Weekly Review als Read-Time-Join