Rename MuJoCo WASM output artifacts to mujoco.*.

This change updates the Emscripten build to output files named `mujoco.js`, `mujoco.wasm`, and `mujoco.d.ts` instead of `mujoco_wasm.*`. The internal CMake target name remains `mujoco_wasm` to avoid conflicts. The package name in `package.json` is also updated to `mujoco`. New enum tests are added.

PiperOrigin-RevId: 875140314
Change-Id: Ie03e0d1db2d03dd8582d5bfcb260b3d33549c2c9

wasm/CMakeLists.txt

@@ -46,13 +46,19 @@ set(EMCC_LINKER_FLAGS
     "-s DISABLE_EXCEPTION_CATCHING=0"
     "-gsource-map"
     "-g"
-    "--emit-tsd mujoco_wasm.d.ts"
+    "--emit-tsd mujoco.d.ts"
 )
 string (REPLACE ";" " " EMCC_LINKER_FLAGS_STR "${EMCC_LINKER_FLAGS}")
 
 add_executable(mujoco_wasm ${MUJOCO_WASM_FILES})
 
-set_target_properties(mujoco_wasm PROPERTIES LINK_FLAGS "${EMCC_LINKER_FLAGS_STR}")
+# Keep the internal target name distinct to avoid colliding with the native
+# `mujoco` library target, but emit artifacts named `mujoco.*` by setting the
+# output name. Also apply the emscripten linker flags to the wasm target.
+set_target_properties(mujoco_wasm PROPERTIES
+    LINK_FLAGS "${EMCC_LINKER_FLAGS_STR}"
+    OUTPUT_NAME "mujoco"
+)
 
 target_link_libraries(mujoco_wasm ccd lodepng mujoco tinyxml2 qhullstatic_r)