fix: resolve JS component action conflict and unit test visibility

- Make JS component WIT file names unique to prevent action conflicts
- Add public visibility to unit_tests for language_support accessibility

Resolves CI build failures where multiple JS components created the same
component.wit symlink and test suites could not access unit tests.

Author: avrabe

js/defs.bzl

@@ -46,7 +46,7 @@ def _js_component_impl(ctx):
     )
 
     # Copy WIT file to workspace (needed for jco componentize)
-    wit_dest = ctx.actions.declare_file("component.wit")
+    wit_dest = ctx.actions.declare_file(ctx.attr.name + "_component.wit")
     ctx.actions.symlink(
         output = wit_dest,
         target_file = wit_file,

test/unit/BUILD.bazel

@@ -104,4 +104,5 @@ test_suite(
         ":test_wit_library_basic",
         ":test_wit_library_with_deps",
     ],
+    visibility = ["//visibility:public"],
 )