fix(@vben-core/form-ui): restore lock screen form submission (#8195)

* fix(@vben-core/form-ui): avoid stale form context access

* fix(@vben/playground): constrain date range codec fields

* test(@vben-core/form-ui): harden benchmark fixtures

* docs(@vben/docs): document form runtime and benchmarks

* fix(@vben/docs): 明确 getValues/submit 返回值及 submit 参数类型

docs/src/en/components/common-ui/vben-form.md

@@ -207,7 +207,7 @@ Create the form through `useVbenForm`:
 
 ## Typed Values and Slots
 
-Use `useVbenForm<TFormValues, TSubmitValues>` to declare component-facing form values and submission values separately. Schema, slots, selectors, and `setValues` use `TFormValues`; `getValues`, submit, and the first `handleSubmit` argument use `TSubmitValues`. Pass one generic when both shapes are identical.
+Use `useVbenForm<TFormValues, TSubmitValues>` to declare component-facing form values and submission values separately. Schema, slots, selectors, and `setValues` use `TFormValues`; `getValues()` and `submit()` return `Promise<TSubmitValues>`, while `submit()` only accepts an optional native `Event`; the first `handleSubmit` argument is `TSubmitValues`. Pass one generic when both shapes are identical.
 
 ```vue
 <script setup lang="ts">
@@ -281,6 +281,28 @@ const [Form, formApi] = useVbenForm({
 
 `schema.valueFormat`, `fieldMappingTime`, and `arrayToStringFields` remain runtime-compatible but are deprecated. When a codec is configured it takes precedence and deprecated transforms are ignored.
 
+## Performance Benchmarks
+
+The form benchmarks cover component initialization, single-field and batch updates, reset, Zod validation, dynamic schemas, dependencies, codec encoding and snapshots, plus array editing, row mutations, and child-schema updates. Run the complete benchmark suite with:
+
+```bash
+pnpm test:benchmark
+```
+
+To run only the form benchmarks, pass both files explicitly:
+
+```bash
+pnpm exec vitest bench --run packages/@core/ui-kit/form-ui/__tests__/form-component-performance.benchmark.ts packages/@core/ui-kit/form-ui/__tests__/form-performance.benchmark.ts
+```
+
+Use benchmark results to compare relative changes on the same machine and runtime; do not treat one run's absolute timings as portable thresholds. Stop CPU-intensive development servers first and keep the Node.js version consistent. Benchmark files are not included in the regular `test:unit` command.
+
+::: warning Mounted form context
+
+`formApi.form` is the `FormContextApi` injected after `<Form />` mounts. Do not destructure or cache `form` from the second `useVbenForm` return value during setup, because that captures the pre-mount empty reference. Prefer mount-aware public methods such as `getRawValues()`, `setFieldError()`, `setFieldValue()`, and `validate()` for business actions. Access fine-grained subscription methods on `formApi.form` only from an already-mounted form context.
+
+:::
+
 ## Key API Notes
 
 - `useVbenForm` returns `[Form, formApi]`
@@ -295,7 +317,7 @@ const [Form, formApi] = useVbenForm({
 - `handleSubmit(values, rawValues)` receives the formatted payload and its corresponding raw snapshot
 - `fieldMappingTime`, `arrayToStringFields`, and `schema.valueFormat` are deprecated compatibility options
 - `codec.encode` defines the `getValues()` payload and `codec.decode` powers complete `setSubmitValues()` fills
-- `formApi.form` is the stable `FormContextApi`; raw TanStack generics are intentionally not exposed
+- `formApi.form` exposes the mounted `FormContextApi`; do not destructure or cache it before `<Form />` mounts
 - prefer `formApi.form.useFieldValue`, `useFieldValues`, and `useFieldError` for fine-grained subscriptions; use `useValues` only when the whole form is required
 - `useSelector` remains the compatibility selector for combined `{ values, errors, meta }` state
 - legacy `setupVbenForm({ defineRules })` still works, warns once in development, and is silent in production; use `rules` for new code