Add a fish version of the Android env helper

Only the env helper needs a per-shell variant, since it has to mutate the
calling shell; android-setup.sh is executed rather than sourced and already
works from fish.

The fish version finds NDK/JDK candidates via `find` rather than globs because
fish raises an error on a wildcard matching nothing, and "SDK with no ndk/
directory yet" is a normal state the helper has to report cleanly.

Also switch the bash helper's NDK selection to `find | sort -V` so the two
agree: glob order is lexicographic, which would rank 9.x above 10.x. Verified
both pick the same NDK and JDK on this machine and against a fixture with
9.0.111 / 10.0.222 / 28.2.333 / 30.0.999-beta2 installed.

scripts/android-env.sh

@@ -21,14 +21,15 @@ _mtgc_android_env() {
     fi
 
     # --- NDK: newest *stable* installed (skip beta/rc/canary) ---
+    # `sort -V` so 9.x doesn't outrank 10.x the way plain lexicographic would.
     local best=""
-    for d in "$sdk"/ndk/*; do
-        [ -d "$d" ] || continue
+    while IFS= read -r d; do
+        [ -n "$d" ] || continue
         case "$(sed -n 's/^Pkg.Revision *= *//p' "$d/source.properties" 2>/dev/null)" in
             *beta*|*rc*|*canary*) continue ;;
         esac
         best="$d"
-    done
+    done < <(find "$sdk/ndk" -mindepth 1 -maxdepth 1 -type d 2>/dev/null | sort -V)
     ndk="$best"
     if [ -z "$ndk" ]; then
         echo "android-env: no stable NDK under $sdk/ndk (run ./scripts/android-setup.sh)" >&2