⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Install the cleanup trap before creating side effects.

The lock file (line 104) and TMP_DIR (line 107) are created before trap cleanup EXIT INT TERM is installed on line 121. If SIGINT/SIGTERM arrives in that window (e.g., during mktemp), the shell takes the default action and exits without running cleanup, leaving an orphaned lock file and a temp dir behind — and on next run the user is told a previous run was killed even though nothing was checked out. Move the trap installation to immediately after ORIGINAL_REF is captured, then write the lock and create the temp dir.

 ORIGINAL_REF=$(git symbolic-ref --quiet --short HEAD 2>/dev/null || git rev-parse HEAD)
-echo "$ORIGINAL_REF" > "$LOCK_FILE"
-
-# Temp files for CSV captures
-TMP_DIR=$(mktemp -d -t maxgraph-sizes-XXXXXX)
-FROM_CSV="$TMP_DIR/from.csv"
-TO_CSV="$TMP_DIR/to.csv"
+TMP_DIR=""
 
 cleanup() {
   local status=$?
+  trap - EXIT INT TERM
   echo >&2
   echo "Restoring original ref: $ORIGINAL_REF" >&2
   git checkout --quiet "$ORIGINAL_REF" 2>/dev/null || \
     echo "Warning: failed to restore $ORIGINAL_REF. Run 'git checkout $ORIGINAL_REF' manually." >&2
-  rm -rf "$TMP_DIR"
+  [[ -n "$TMP_DIR" ]] && rm -rf "$TMP_DIR"
   rm -f "$LOCK_FILE"
   exit $status
 }
 trap cleanup EXIT INT TERM
+
+echo "$ORIGINAL_REF" > "$LOCK_FILE"
+TMP_DIR=$(mktemp -d -t maxgraph-sizes-XXXXXX)
+FROM_CSV="$TMP_DIR/from.csv"
+TO_CSV="$TMP_DIR/to.csv"

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

cleanup runs twice on INT/TERM.

With trap cleanup EXIT INT TERM, a SIGINT invokes cleanup, which calls exit $status, which in turn fires the EXIT trap and runs cleanup again. The second pass re-prints "Restoring original ref: …", attempts another checkout (harmless but noisy), and tries to rm -f an already-removed lock. Clear the traps at the top of cleanup to make it idempotent.

 cleanup() {
   local status=$?
+  trap - EXIT INT TERM
   echo >&2
   echo "Restoring original ref: $ORIGINAL_REF" >&2

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Silent column mismatch in CSV parsing.

dict(zip(header, values)) silently truncates to the shorter of the two lists. If build-all-examples.bash ever emits a CSV with a header/values length mismatch (or trailing garbage line picked up by tail -n 2), the script will produce a partial table with no warning. A length check before zipping turns this into a loud failure that matches the rest of the script's strict posture.

 def load(path):
     with open(path) as f:
         lines = [ln.rstrip("\n") for ln in f if ln.strip()]
     header = lines[0].split(",")
     values = lines[1].split(",")
+    if len(header) != len(values):
+        sys.exit(
+            f"Error: CSV header/values column count mismatch in {path} "
+            f"({len(header)} vs {len(values)})."
+        )
     return dict(zip(header, values))