export run: commit= im Marker je Seite statt je Ziel - jede Datei nennt den letzten Commit ihrer eigenen Seite, ermittelt in einem git log über alle ausgewählten Pfade (Pfade über stdin und wörtlich), das Manifest behält den neuesten Commit über alle; ein Commit schreibt nur die Dateien der Seiten neu, die er berührt hat, plus Dateien, deren Links sich ändern. Erster Lauf nach dem Update schreibt jede Datei einmal neu (#221); 10.1.0-beta.12

Files changed:
- CHANGES.md
- VERSION
- docs/how-to/export-to-a-synced-folder.md
- docs/reference/commands/exports.md
- docs/reference/configuration.md
- tools/CONTRACT.md
- tools/chemenu/commands/export_cmd.py
- tools/chemenu/guideline_export.py
- tools/chemenu/page_export.py
- tools/chemenu/tests/test_export_run.py

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

tools/CONTRACT.md

@@ -2456,7 +2456,7 @@ Write the derived, read-only reading copy of `kb/` into the folders the `export`
 **NOTES**
 
 - An export is derived: regenerated from `kb/` on every run, never edited, never read back into the wiki. Each target names its pages with an allowlist of `search --field` predicates (`include`: a list of selections, AND within one, OR across them), a handler (`markdown`, or `command` for the operator's converter) and the folder (`path`, outside the instance). Nothing is exported that no selection names.
-- Every Markdown file starts with a frontmatter block whose `wikitool_export` line says `kind=pages instance=<origin URL without userinfo, or local> commit=<newest commit touching a selected page>`, followed by `title`, `type`, `summary`, `modified` where the page has them (`frontmatter: summary`, the default; `minimal` keeps only the marker, `full` the whole frontmatter), then the page text. A file keeps its path below `kb/`. A wikilink to an exported page becomes a relative Markdown link (`links: relative`, the default) or plain text (`links: text`); a link to a page that is not exported is always plain text. Footnote markers stay; code is never rewritten. LF endings, no timestamp: the same pages give the same bytes.
+- Every Markdown file starts with a frontmatter block whose `wikitool_export` line says `kind=pages instance=<origin URL without userinfo, or local> commit=<newest commit touching this page>`, followed by `title`, `type`, `summary`, `modified` where the page has them (`frontmatter: summary`, the default; `minimal` keeps only the marker, `full` the whole frontmatter), then the page text. A file keeps its path below `kb/`. A wikilink to an exported page becomes a relative Markdown link (`links: relative`, the default) or plain text (`links: text`); a link to a page that is not exported is always plain text. Footnote markers stay; code is never rewritten. LF endings, no timestamp: the same pages give the same bytes, and a commit that touches one page rewrites that page's file alone - plus any file whose links change because a page entered or left the selection. The manifest's `commit` is the newest commit touching any selected page; all of them come from one `git log`, however many pages are selected.
 - Handler `command`: the Markdown is rendered into a staging directory, the program of `export.commands` runs with no shell, stdin closed and a timeout of 300 s, and receives the Markdown directory and an empty output directory as its last two arguments. On exit 0 the regular files in the output directory (recursively) become the target's content; any other end leaves the target unchanged and prints the end of its stderr. The staging directory is always removed.
 - The folder is only ever touched by what it holds in its manifest, `.wikitool-export.json`: the files an earlier run wrote, each with its sha256. A run removes only manifest files that are no longer exported (and folders it created, once empty), rewrites a manifest file that is missing, leaves every other file byte for byte as it was, and writes nothing - not even a modification time - for a file that did not change. A run that changes nothing writes nothing at all.
 - Refuses a target, before writing anything into it: a non-empty folder with no manifest (it is somebody's, not an export), a manifest file that was changed in the folder since the last run (naming it), a foreign file where an exported one belongs, an empty selection (it would delete the earlier export), an unknown field in a predicate. A missing folder is created.