fix(form): drop AntD Form/FormItem/useForm bridge, use native React state

[Agions]

🐱 fix(form): drop AntD Form/FormItem/useForm bridge, use native React state

Why

User direction: project doesn't need AntD compat, doesn't need AntD structural config.

The <Form>/<FormItem>/useForm shim in shared/components/ui/ui-components.tsx was fake AntD — neither real AntD nor real RHF, just a 97-line wrapper that bridged useRhfForm to AntD's setFieldsValue/validateFields/getFieldValue API. The Phase 2 dead-code cleanup (#6) exposed it via broken jest-skipped ProjectEdit/ProjectDetail tests that depended on this shim.

The shim had 4 call sites, and 3 of them never used the validation/form-library features at all — they only used form as a value holder for 2-12 primitive fields with no cross-field validation. Native useState is the simplest correct form library for these cases.

What changed

src/shared/components/ui/ui-components.tsx (-97 lines):

• ❌ <Form> component (97 lines, fake AntD onFinish bridge)
• ❌ <FormItem> component + FormWithItem compound pattern
• ❌ useForm re-export (was useRhfForm as useForm)
• ❌ FormValues type
• ❌ ValidationRule/FormProps/FormItemProps interfaces
• ❌ useRhfForm import
• ✅ Added comment block explaining the new contract: use useState for simple forms, or import { useForm } from 'react-hook-form' directly for complex ones
• ✅ Preserved non-Form re-exports (Modal/Spin/Space/Empty/Button/Card/Input/etc.) — 3 of 7 importers don't touch Form and need no changes

4 call sites converted to native React:

File	Change
pages/project-edit/ProjectEditPage.tsx	useForm() → useState for name/description; form.setFieldsValue → setName(); form.validateFields() → if (!name.trim()); form.getFieldValue('name') → name; form.getFieldsValue() → inline literal. Page never rendered <Form> anyway.
features/script/components/ScriptGenerator.tsx	8 useState hooks; <Form onFinish={handleGenerate}> → native <form onSubmit>; 8 <FormItem> → <label> + controlled <Input>/<Select>/<RadioGroup>; form.handleSubmit(handleGenerate)() (2 sites) → void handleGenerate(); submit onClick → htmlType="submit"
shared/components/business/CompositionStudio/GlobalSettingsForm.tsx	Was a dead shell (Slider/InputNumber/Select had no value/onChange) — now functional: 4 useState + onSave wire-up. Also adds onSave submit button.
shared/components/business/CompositionStudio/FrameEditForm.tsx	Same dead-shell pattern, now 12 useState + save/reset buttons. CameraMotion | null → CameraMotion | undefined (Select doesn't accept null value).
shared/components/business/CompositionStudio/index.tsx	3 <FormItem label=> → plain <label> (skeleton-only, no state needed)

Verification

Check	Result
npm run lint --quiet	✅ 0 errors
npx tsc --noEmit	✅ 0 errors
npm test --runInBand (90 suites)	✅ 1596 pass, 4 skip, 0 fail
npm run build	✅ OK

Bundle impact

• react-vendor chunk: 311 KB → 287 KB (~24 KB smaller — react-hook-form no longer pulled into vendor chunk since no UI shim re-exports it)
• ui-vendor chunk: unchanged (118 KB)

Diff

 6 files changed, 361 insertions(+), 400 deletions(-)

Out of scope (intentionally NOT touched)

• The __tests__/pages/project-{edit,detail}.test.tsx jest-skip entries stay in place. Now that the form refactor is done, the underlying useState is honest, but the ProjectEditPage still needs an <Input> UI element to be user-editable. That's a separate feature (real project metadata form), not a refactor. Tests can be re-enabled when that UI lands.
• Modal/Spin/Space/Empty/Button/Card/Input re-exports stay — they're AntD-style names but shadcn/RHF implementations, not part of the Form/FormItem bridge.
• The FormWithItem as Form export for non-Form usage is gone too (was unused in the codebase).

Lesson learned (for future agent runs)

The fake-AntD shim is a textbook example of "in-progress refactor" residue: someone started bridging RHF to AntD-style API, shipped 97 lines of bridging code, then 4 call sites used it inconsistently and never finished the migration. Both Phase 1 (back-compat shims) and this form refactor cleanup the same kind of dead scaffolding. If you find yourself reaching for an <Form>/<FormItem> API, ask first: does this need a form library, or is useState enough?