Simplify: remove dead code and redundancy across vue app

- Delete ObjectBasic (defined, never imported)
- ObjectShort: remove unused node prop
- exporter: export stressorToString; use in patchBarMeta (removes inline duplicate)
- PaneFO: import stressorToString from exporter; extract H4 style constant,
  shapeSection() helper, instrOnChange() helper; remove apply param from
  makeChangeHandler (was always () => markDirty()); remove unnecessary ?.
  on always-initialized arrays (variations, labelSpecs, subvariations)
- PaneSubObjects: explicit hasChildren on all item kinds; bars at score
  level get hasChildren based on voices; remove stale kind-list fallback
- ast-parser coerce(): remove unreachable s.trim() check ('' handled above)
- PaneCP: fix post-export synthesisStatus reset to use real field names

static/components/ObjectShort.js

@@ -2,7 +2,7 @@ import { h } from 'vue';
 
 // One-line summary row with a drill-down chevron.
 export const ObjectShort = {
-    props: ['node', 'label', 'typeTag', 'focused', 'hasChildren'],
+    props: ['label', 'typeTag', 'focused', 'hasChildren'],
     emits: ['focus', 'drillDown'],
     setup(props, { emit }) {
         return () => h('li', {