Commits of agents carry a co-author trailer naming the model

A git wrapper (docker/git-coauthor -> /usr/local/lib/codecraft/bin/git) adds
--trailer "$CODECRAFT_COMMIT_TRAILER" right after the commit subcommand; the
agent shell puts it first on PATH and sets the trailer in the script itself
(works inside the sandbox, which clears the environment). Default text:
"Co-Authored-By: {model} ({provider}) via CodeCraft" (server.commit_trailer,
Settings -> General; empty = off). Git skips duplicates (amend, model wrote it).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/i18n/de.ts

@@ -770,6 +770,9 @@ export const de: Messages = {
   "settings.smallModelHint": "Für Session-Titel. Die Komprimierung nutzt das Session-Modell.",
   "settings.currency": "Währung",
   "settings.autoCompact": "Auto-Komprimierung bei",
+  "settings.commitTrailer": "Commit-Vermerk der Agenten",
+  "settings.commitTrailerOff": "aus",
+  "settings.commitTrailerHint": "Wird als Trailer an jeden Git-Commit eines Agenten angehängt. {model} = Modellname, {provider} = Anbieter, {model_id} = Modell-ID. Leer = aus. Deine eigenen Commits bleiben unverändert.",
   "settings.autoCompactHint": "Anteil des Kontextfensters (0 = aus).",
   "settings.craft": "Craft-Modus",
   "settings.cleanRoom": "Clean Room",