Macros 2.0 - list-supported Macros Autocomplete Improvements (#5135)

* fix(macros): prevent list-arg macros from accepting scoped content

List-arg macros now correctly reject scoped content since they only accept arbitrary inline arguments. Updated validation logic in autocomplete, scope detection, and CST walker to check for `list === null` before allowing scopes. Also improved list item hint display to show total count when typing additional items.

* feat(macros): display min/max constraints for list arguments in autocomplete hints

Add visual indication of list argument constraints by showing min/max values in autocomplete hints. List items now display "(list, min: X, max: Y)" or "(variable-length list)" when no constraints exist. Includes new CSS styling for smaller, dimmed hint text.

* feat(macros): validate list argument min/max constraints and improve warning display

Add validation for list argument constraints (min/max) with specific error messages when too few or too many list items are provided. Continue highlighting current argument position even when warnings are present (except where semantically invalid), allowing users to navigate back to valid arguments while seeing "too many arguments" warnings.

public/css/macros.css

@@ -566,6 +566,11 @@
     font-size: 0.8em;
 }
 
+.macro-ac-arg-hint .macro-ac-arg-hint-small {
+    font-size: 0.85em;
+    opacity: 0.8;
+}
+
 .macro-ac-hint-type {
     font-family: var(--monoFontFamily);
     font-size: 0.85em;