fix(interpreter): resolve nameref for ${!ref[@]} key enumeration (#855)

The ArrayIndices handler in expand_word_to_string was not resolving namerefs before looking up keys, causing ${!ref[@]} to return empty when ref is a nameref to an associative array.

Closes #846

Author: chaliy

crates/bashkit/src/interpreter/mod.rs

@@ -5897,11 +5897,12 @@ impl Interpreter {
                     result.push_str(&self.expand_array_access_part(name, index));
                 }
                 WordPart::ArrayIndices(name) => {
-                    if let Some(arr) = self.assoc_arrays.get(name) {
+                    let resolved = self.resolve_nameref(name);
+                    if let Some(arr) = self.assoc_arrays.get(resolved) {
                         let mut keys: Vec<_> = arr.keys().cloned().collect();
                         keys.sort();
                         result.push_str(&keys.join(" "));
-                    } else if let Some(arr) = self.arrays.get(name) {
+                    } else if let Some(arr) = self.arrays.get(resolved) {
                         let mut indices: Vec<_> = arr.keys().collect();
                         indices.sort();
                         let index_strs: Vec<String> =

crates/bashkit/tests/spec_cases/bash/nameref-assoc.test.sh

@@ -82,6 +82,22 @@ count_entries data
 3
 ### end
 
+### nameref_assoc_key_enumeration_string
+# Nameref key enumeration via ${!ref[@]} in string context
+show() {
+  local -n ref="$1"
+  for k in "${!ref[@]}"; do
+    echo "${k}=${ref[$k]}"
+  done | sort
+}
+declare -A m=([a]=1 [b]=2 [c]=3)
+show m
+### expect
+a=1
+b=2
+c=3
+### end
+
 ### nameref_overwrite_assoc_key
 # Nameref overwrite existing key in associative array
 update() {