chore: harden co-author stripping hooks and gitignore lefthook wrappers

Use portable sed in prepare-commit-msg (macOS-safe), add lefthook
prepare-commit-msg strip, and ignore lefthook-generated hook wrappers.

Author: Patel230

.githooks/prepare-commit-msg

@@ -8,16 +8,9 @@ if [ "$COMMIT_SOURCE" = "merge" ] || [ "$COMMIT_SOURCE" = "squash" ]; then
   exit 0
 fi
 
-# Strip Co-authored-by lines
-sed -i.bak "/^Co-authored-by:/d" "$COMMIT_MSG_FILE" 2>/dev/null || \
-  sed -i  "/^Co-authored-by:/d" "$COMMIT_MSG_FILE"
+# Strip Co-authored-by lines (portable sed — works on macOS and Linux).
+sed '/^[Cc]o-[Aa]uthored-[Bb]y:/d' "$COMMIT_MSG_FILE" > "${COMMIT_MSG_FILE}.tmp" && mv "${COMMIT_MSG_FILE}.tmp" "$COMMIT_MSG_FILE"
 
-# Remove trailing blank lines
-sed -i.bak -e :a -e "/^
-*$/{$d;N;ba" -e "}" "$COMMIT_MSG_FILE" 2>/dev/null || \
-  sed -i  -e :a -e "/^
-*$/{$d;N;ba" -e "}" "$COMMIT_MSG_FILE"
-
-# Clean up backup files
-rm -f "${COMMIT_MSG_FILE}.bak"
+# Remove trailing blank lines.
+sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' "$COMMIT_MSG_FILE" > "${COMMIT_MSG_FILE}.tmp" 2>/dev/null && mv "${COMMIT_MSG_FILE}.tmp" "$COMMIT_MSG_FILE" || true
 

.gitignore

@@ -24,3 +24,8 @@ dist/
 .commandcode/
 .DS_Store
 coverage.out
+
+# Lefthook-generated wrappers (tracked .githooks/prepare-commit-msg is canonical)
+.githooks/commit-msg
+.githooks/pre-push
+.githooks/pre-commit.old

lefthook.yml

@@ -116,3 +116,12 @@ commit-msg:
         # Strip Co-authored-by: trailers that AI tools (Claude, Cursor, etc.) add.
         # This enforces the rule that commits list only the human author.
         sed '/^[Cc]o-[Aa]uthored-[Bb]y:/d' "{1}" > "{1}.tmp" && mv "{1}.tmp" "{1}"
+
+# ---------------------------------------------------------------------------
+# prepare-commit-msg — strip AI co-author trailers after tools inject them.
+# ---------------------------------------------------------------------------
+prepare-commit-msg:
+  commands:
+    strip-co-authored-by:
+      run: |
+        sed '/^[Cc]o-[Aa]uthored-[Bb]y:/d' "{1}" > "{1}.tmp" && mv "{1}.tmp" "{1}"