fix(bb): cache Emscripten .js loader and .worker.mjs siblings of .wasm targets

preset_cache_paths only matched targets by name + native sibling extensions
(.exe, .node, lib*.a). Emscripten emits a .js loader and .worker.mjs pthread
worker alongside every .wasm exec target as a unit, so cache_upload missed
them and a wasm-threads cache hit restored barretenberg.wasm without the
matching barretenberg.js.

bb-ts/scripts/copy_wasm.sh then unconditionally copies cpp/build-wasm-threads/
bin/barretenberg.js into dest/<flavor>/barretenberg_wasm/, which fast-mode CI
hits before any cache miss can rebuild the cpp side, producing:
  cp: cannot stat '../cpp/build-wasm-threads/bin/barretenberg.js': No such file or directory

Extend preset_cache_paths so any target ending in .wasm also picks up the
$stem.js and $stem.worker.mjs siblings from the same bin/ directory.

Author: AztecBot

barretenberg/cpp/bootstrap.sh

@@ -87,6 +87,15 @@ function preset_cache_paths {
       find $build_dir/bin $build_dir/lib \
         -maxdepth 1 \( -name "$t" -o -name "$t.exe" -o -name "$t.node" -o -name "lib${t}.a" \) \
         2>/dev/null
+      # Emscripten emits a .js loader and a .worker.mjs pthread worker as
+      # side-outputs of any .wasm executable target; cache them next to the
+      # .wasm so consumers like bb.js see a complete artifact set on cache hit.
+      if [[ "$t" == *.wasm ]]; then
+        local stem="${t%.wasm}"
+        find $build_dir/bin -maxdepth 1 \
+          \( -name "$stem.js" -o -name "$stem.worker.mjs" \) \
+          2>/dev/null
+      fi
     done
   fi
 }