load_module and load_inline_module drove run_event_loop to full idle
before reading the module's mod_evaluate result. A page timer keeps the
loop busy forever (Vite's HMR / React-Refresh client installs a
setInterval), so the preamble inline module burned the entire budget
waiting for an idle that never came, and the later module that mounts the
app was skipped, leaving #root empty while the production preview rendered
fine (issue #374).
Drive the event loop and the mod_evaluate result together and return as
soon as the module finishes evaluating, so a busy background timer no
longer starves the remaining modules. Post-eval async work is still
drained by the normal post-load settle.
Fixes#374.
SGavrl
d3a8b9a482