Voice Studio "Save design as profile" passed buildDesignInstruct()'s RETURN
OBJECT ({instruct, unsupported, duplicates}) straight to FormData.append, which
string-coerced it to the literal "[object Object]". That got persisted into
voice_profiles.instruct and 400'd on first preview/use with "Unsupported instruct
items found in [object Object]" (#550#545#542#537#530#525).
Fix the whole class + heal already-poisoned data (backward-compatible-data rule):
- CloneDesignTab.jsx:609 — pass `.instruct` (the string), not the builder object.
- useProfiles.js — append via new instructToFormValue() helper, which extracts
`.instruct` if an object ever slips through again (defense-in-depth).
- omnivoice/_resolve_instruct — drop the "[object Object]" sentinel instead of
raising, so any value that slips through (e.g. generation_history) degrades to
neutral conditioning rather than a hard 400. A genuine unsupported token still
raises (keeps the #114/#115 user feedback).
- migration 0006 — UPDATE voice_profiles SET instruct='' WHERE it's the sentinel,
idempotent + table-guarded, to heal profiles saved on the buggy build.
Tests (fail-before/pass-after): frontend voiceInstruct (instructToFormValue never
yields "[object Object]"); backend _resolve_instruct tolerates the sentinel but
still rejects a real bad token; alembic 0006 heals a poisoned row, leaves a
healthy one untouched. Frontend 9 passed + typecheck clean; backend 5 passed.
Co-authored-by: mergetest <test@local>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
