Fix removing empty elements to avoid trailing commas

src/utils.py

@@ -60,7 +60,8 @@ def parse_options(raw: str) -> list[str]:
 
             # Generate cartesian product
             for combo in product(*current_block):
-                result.append(", ".join(combo))
+                parts = [p for p in combo if p.strip()]
+                result.append(", ".join(parts) if parts else "")
 
         elif stripped == "---":
             if in_combine:

tests/test_parse_options.py

@@ -43,8 +43,10 @@ def test_combine_three_lists():
 def test_combine_empty_line_in_list():
     raw = "@combine\na\n\n---\nb\n@end"
     result = parse_options(raw)
-    assert ", b" in result  # empty + b
+    assert "b" in result
     assert "a, b" in result
+    # Empty element combined with b gives just "b"
+    assert ", b" not in result
 
 
 def test_multiple_combine_blocks():

web/prompt_option_picker.js

@@ -75,7 +75,8 @@ const parseOptions = (raw) => {
                     const next = [];
                     for (const a of acc) {
                         for (const b of list) {
-                            next.push(a ? `${a}, ${b}` : b);
+                            const parts = [a, b].filter((p) => p.trim() !== "");
+                            next.push(parts.join(", "));
                         }
                     }
                     return next;