fix: replace PrimeVue FloatLabel in WidgetTextarea with CSS-only IFTA label (#9076)

## Summary

Replace PrimeVue `FloatLabel` + `Textarea` in `WidgetTextarea` with a
CSS-only IFTA label and a new shadcn-vue Textarea component, fixing the
label-obscures-content bug.

<img width="965" height="754" alt="image"
src="https://github.com/user-attachments/assets/cab98527-834c-496d-a0ef-942fb21fd862"
/>


## Changes

- **What**: Add `src/components/ui/textarea/Textarea.vue` — thin wrapper
around native `<textarea>` with `cn()` class merging and `defineModel`.
Rewrite `WidgetTextarea.vue` to use a plain `<div>` wrapper with an
absolutely-positioned label and the new Textarea, replacing PrimeVue's
`FloatLabel variant="in"`. Add Storybook stories (Default, Disabled,
WithLabel). Update tests to remove PrimeVue plugin setup.

## Review Focus

- The label uses `absolute left-3 top-1.5 z-10 text-xxs` positioning —
verify it clears textarea content with `pt-5` padding
- `filteredProps` forwards widget options to a native textarea via
`v-bind="restAttrs"` — unknown attrs are silently ignored by the browser

Supersedes #8536

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9076-fix-replace-PrimeVue-FloatLabel-in-WidgetTextarea-with-CSS-only-IFTA-label-30f6d73d3650816fabe5ee30de0c793e)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

src/renderer/extensions/vueNodes/widgets/components/WidgetTextarea.test.ts

@@ -1,6 +1,4 @@
 import { mount } from '@vue/test-utils'
-import PrimeVue from 'primevue/config'
-import Textarea from 'primevue/textarea'
 import { describe, expect, it } from 'vitest'
 
 import type { SimplifiedWidget } from '@/types/simplifiedWidget'
@@ -28,10 +26,6 @@ function mountComponent(
   placeholder?: string
 ) {
   return mount(WidgetTextarea, {
-    global: {
-      plugins: [PrimeVue],
-      components: { Textarea }
-    },
     props: {
       widget,
       modelValue,

src/renderer/extensions/vueNodes/widgets/components/WidgetTextarea.vue

@@ -1,37 +1,45 @@
 <template>
-  <FloatLabel
-    variant="in"
-    :unstyled="hideLayoutField"
+  <div
     :class="
       cn(
-        'rounded-lg space-y-1 focus-within:ring focus-within:ring-component-node-widget-background-highlighted transition-all',
+        'relative rounded-lg focus-within:ring focus-within:ring-component-node-widget-background-highlighted transition-all',
         widget.borderStyle
       )
     "
   >
+    <label
+      v-if="!hideLayoutField"
+      :for="id"
+      class="pointer-events-none absolute left-3 top-1.5 z-10 text-xxs text-muted-foreground"
+    >
+      {{ displayName }}
+    </label>
     <Textarea
       v-bind="filteredProps"
       :id
       v-model="modelValue"
-      :class="cn(WidgetInputBaseClass, 'size-full text-xs resize-none')"
+      :class="
+        cn(
+          WidgetInputBaseClass,
+          'size-full text-xs resize-none',
+          !hideLayoutField && 'pt-5'
+        )
+      "
       :placeholder
       :readonly="isReadOnly"
-      fluid
       data-capture-wheel="true"
       @pointerdown.capture.stop
       @pointermove.capture.stop
       @pointerup.capture.stop
       @contextmenu.capture.stop
     />
-    <label v-if="!hideLayoutField" :for="id">{{ displayName }}</label>
-  </FloatLabel>
+  </div>
 </template>
 
 <script setup lang="ts">
-import FloatLabel from 'primevue/floatlabel'
-import Textarea from 'primevue/textarea'
 import { computed, useId } from 'vue'
 
+import Textarea from '@/components/ui/textarea/Textarea.vue'
 import type { SimplifiedWidget } from '@/types/simplifiedWidget'
 import { useHideLayoutField } from '@/types/widgetTypes'
 import { cn } from '@/utils/tailwindUtil'