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/whatsnew.ts

@@ -3,6 +3,10 @@
  * under "unreleased"; scripts/release.sh renames the key to the release version.
  */
 export const WHATS_NEW: Record<string, { en: string[]; de: string[] }> = {
+  unreleased: {
+    en: ["Git commits of agents name the model: “Co-Authored-By: <model> (<provider>) via CodeCraft” (Settings → General)"],
+    de: ["Git-Commits von Agenten nennen das Modell: „Co-Authored-By: <Modell> (<Anbieter>) via CodeCraft“ (Einstellungen → Allgemein)"],
+  },
   "202611-00020": {
     en: ["Reverse engineering: decompile with Ghidra can be enabled for any mode (Settings → Agents & commands), now also for raw firmware"],
     de: ["Reverse Engineering: Dekompilieren mit Ghidra lässt sich für jeden Modus einschalten (Einstellungen → Agenten & Befehle), jetzt auch für rohe Firmware"],