[docs] Add commit message format convention

diff --git a/CLAUDE.md b/CLAUDE.md
index e28ac20cd344daea0d10428423cdc771fbb61c7d..9239c692cd439e42d525581539df004504eec38e 100644 (file)
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -41,6 +41,14 @@ Core service types:
   home directory. Strips the first path component of each dotfile to derive its
   $HOME-relative target.
 
+# Style
+
+- Use `[tag] <title>.` format for commit subjects: a short tag in
+  brackets, a sentence-case title ending with a period, a blank line,
+  then one or more description paragraphs.
+- End git commit messages with:
+  Co-Authored-By: Claude <noreply@anthropic.com>
+
 # Build Queue
 
 Populate the build queue early to avoid an extra dialog at Stop time. If the