Run 8271 failed in the image build: "[vite:vue] Cannot read properties of undefined (reading 'scoped')" on moments-shared.css. plugin-vue caches one descriptor per src file and answers ?index=N from whichever component registered it last. RuleEditorSlideOver had moments-shared at block 2, while its other two importers have it at block 1. Step 2's new imports changed the transform order and exposed the bug.
- RuleEditorSlideOver: moments-shared is now loaded with an @import instead of a third <style src>.
- rules-shared.css sat at block 0 in the five panes and at block 1 in LessonDetailView, LessonEditorView and RuleEditorSlideOver, which is the same latent hazard. The three move to block 0.
- tests/test_frontend_shared_styles.py: a guard that every <style src> sheet sits at one index, plus a test that the guard can fail. vue-tsc cannot see this hazard, and vite build only runs after every test has passed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
