diff --git a/web/app/components/base/param-item/__tests__/index-slider.browser.spec.tsx b/web/app/components/base/param-item/__tests__/index-slider.browser.spec.tsx
new file mode 100644
index 00000000000..29f98c344ae
--- /dev/null
+++ b/web/app/components/base/param-item/__tests__/index-slider.browser.spec.tsx
@@ -0,0 +1,30 @@
+import { page, userEvent } from 'vite-plus/test/browser'
+import { render } from 'vitest-browser-react'
+import { ParamItemExample } from './param-item-example'
+
+beforeEach(async () => {
+  await page.viewport(800, 600)
+})
+
+// Native Tab/arrow input must update the caller and numeric field, not just emit a callback.
+it.each([
+  { max: 1, min: 0, value: 0.5, sliderValue: '50', next: 0.51, nextSliderValue: '51' },
+  { max: 10, min: 1, value: 5, sliderValue: '5', next: 6, nextSliderValue: '6' },
+])(
+  'keeps keyboard slider edits in parameter units with max=$max',
+  async ({ max, min, value, sliderValue, next, nextSliderValue }) => {
+    await render(<ParamItemExample value={value} min={min} max={max} />)
+    const slider = page.getByRole('slider', { name: 'Test Param' })
+    const input = page.getByRole('textbox', { name: 'Test Param' })
+    await expect.element(slider).toHaveValue(sliderValue)
+    await input.click()
+    await userEvent.tab()
+    await expect.element(slider).toHaveFocus()
+    await userEvent.keyboard('{ArrowRight}')
+    await expect.element(input).toHaveValue(String(next))
+    await expect.element(slider).toHaveValue(nextSliderValue)
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent(JSON.stringify({ test_param: next }))
+  },
+)
diff --git a/web/app/components/base/param-item/__tests__/index-slider.spec.tsx b/web/app/components/base/param-item/__tests__/index-slider.spec.tsx
deleted file mode 100644
index 0a05eb43df9..00000000000
--- a/web/app/components/base/param-item/__tests__/index-slider.spec.tsx
+++ /dev/null
@@ -1,41 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import userEvent from '@testing-library/user-event'
-import ParamItem from '..'
-
-describe('ParamItem Slider onChange', () => {
-  const defaultProps = {
-    id: 'test_param',
-    name: 'Test Param',
-    enable: true,
-    onChange: vi.fn(),
-  }
-
-  const getSlider = () => screen.getByRole('slider', { name: 'Test Param' })
-
-  it('should divide slider value by 100 when max < 5', async () => {
-    const user = userEvent.setup()
-    render(<ParamItem {...defaultProps} value={0.5} min={0} max={1} />)
-    const slider = getSlider()
-
-    expect(slider).toHaveAttribute('aria-valuenow', '50')
-    expect(slider).toHaveAttribute('aria-valuetext', '0.5')
-
-    slider.focus()
-    await user.keyboard('{ArrowRight}')
-
-    // max=1 < 5, so slider value change (50->51) becomes 0.51
-    expect(defaultProps.onChange).toHaveBeenLastCalledWith('test_param', 0.51)
-  })
-
-  it('should not divide slider value when max >= 5', async () => {
-    const user = userEvent.setup()
-    render(<ParamItem {...defaultProps} value={5} min={1} max={10} />)
-    const slider = getSlider()
-
-    slider.focus()
-    await user.keyboard('{ArrowRight}')
-
-    // max=10 >= 5, so value remains raw (5->6)
-    expect(defaultProps.onChange).toHaveBeenLastCalledWith('test_param', 6)
-  })
-})
diff --git a/web/app/components/base/param-item/__tests__/index.browser.spec.tsx b/web/app/components/base/param-item/__tests__/index.browser.spec.tsx
new file mode 100644
index 00000000000..90283c1576b
--- /dev/null
+++ b/web/app/components/base/param-item/__tests__/index.browser.spec.tsx
@@ -0,0 +1,87 @@
+import { page, userEvent } from 'vite-plus/test/browser'
+import { render } from 'vitest-browser-react'
+import { ParamItemExample } from './param-item-example'
+
+beforeEach(async () => {
+  await page.viewport(800, 600)
+})
+
+describe('ParamItem', () => {
+  it('omits the tooltip trigger when tooltips are disabled', async () => {
+    await render(<ParamItemExample noTooltip tip="Hidden tip" />)
+    await expect.element(page.getByRole('button', { name: 'Test Param' })).not.toBeInTheDocument()
+  })
+
+  it('disables both numeric and slider edits when the parameter is off', async () => {
+    await render(<ParamItemExample enable={false} />)
+    await expect.element(page.getByRole('textbox', { name: 'Test Param' })).toBeDisabled()
+    await expect.element(page.getByRole('slider', { name: 'Test Param' })).toBeDisabled()
+  })
+
+  it('applies text edits to the named parameter and its slider', async () => {
+    await render(<ParamItemExample />)
+    const input = page.getByRole('textbox', { name: 'Test Param' })
+    await input.clear()
+    await userEvent.keyboard('0.8')
+    await expect.element(input).toHaveValue('0.8')
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent('{"test_param":0.8}')
+    await expect
+      .element(page.getByRole('slider', { name: 'Test Param' }))
+      .toHaveAttribute('aria-valuetext', '0.8')
+  })
+
+  it('allows replacing the minimum with a multi-digit value without saving the empty draft', async () => {
+    await render(<ParamItemExample value={1} min={1} max={100} />)
+    const input = page.getByRole('textbox', { name: 'Test Param' })
+    await input.clear()
+    await expect.element(input).toHaveValue('')
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent('{"test_param":1}')
+    await userEvent.keyboard('20')
+    await expect.element(input).toHaveValue('20')
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent('{"test_param":20}')
+    await expect.element(page.getByRole('slider', { name: 'Test Param' })).toHaveValue('20')
+  })
+
+  it('clamps text edits before saving the parameter and updating the slider', async () => {
+    await render(<ParamItemExample />)
+    const input = page.getByRole('textbox', { name: 'Test Param' })
+    await input.clear()
+    await userEvent.keyboard('1.5')
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent('{"test_param":1}')
+    await expect
+      .element(page.getByRole('slider', { name: 'Test Param' }))
+      .toHaveAttribute('aria-valuetext', '1')
+  })
+
+  it('applies the named switch change and disables the parameter controls', async () => {
+    await render(<ParamItemExample hasSwitch />)
+    const toggle = page.getByRole('switch', { name: 'Test Param' })
+    await toggle.click()
+    await expect.element(toggle).not.toBeChecked()
+    await expect
+      .element(page.getByRole('status', { name: 'Enabled parameters' }))
+      .toHaveTextContent('{"test_param":false}')
+    await expect.element(page.getByRole('textbox', { name: 'Test Param' })).toBeDisabled()
+    await expect.element(page.getByRole('slider', { name: 'Test Param' })).toBeDisabled()
+  })
+
+  it('applies the increment step to the saved parameter and both controls', async () => {
+    await render(<ParamItemExample step={0.1} />)
+    await page.getByRole('button', { name: 'Increment value' }).click()
+    await expect.element(page.getByRole('textbox', { name: 'Test Param' })).toHaveValue('0.6')
+    await expect
+      .element(page.getByRole('slider', { name: 'Test Param' }))
+      .toHaveAttribute('aria-valuetext', '0.6')
+    await expect
+      .element(page.getByRole('status', { name: 'Saved parameters' }))
+      .toHaveTextContent('{"test_param":0.6}')
+  })
+})
diff --git a/web/app/components/base/param-item/__tests__/index.spec.tsx b/web/app/components/base/param-item/__tests__/index.spec.tsx
deleted file mode 100644
index 100f7168697..00000000000
--- a/web/app/components/base/param-item/__tests__/index.spec.tsx
+++ /dev/null
@@ -1,169 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import userEvent from '@testing-library/user-event'
-import { useState } from 'react'
-import ParamItem from '..'
-
-describe('ParamItem', () => {
-  const defaultProps = {
-    id: 'test_param',
-    name: 'Test Param',
-    value: 0.5,
-    enable: true,
-    max: 1,
-    onChange: vi.fn(),
-  }
-
-  beforeEach(() => {
-    vi.clearAllMocks()
-  })
-
-  const getSlider = () =>
-    screen.getByLabelText('Test Param', {
-      selector: 'input[type="range"]',
-    })
-
-  describe('Rendering', () => {
-    it('should not render tooltip trigger when noTooltip is true', () => {
-      render(<ParamItem {...defaultProps} noTooltip tip="Hidden tip" />)
-
-      expect(screen.queryByRole('button', { name: 'Test Param' })).not.toBeInTheDocument()
-    })
-  })
-
-  describe('Props', () => {
-    it('should disable InputNumber when enable is false', () => {
-      render(<ParamItem {...defaultProps} enable={false} />)
-
-      expect(screen.getByRole('textbox')).toBeDisabled()
-      expect(getSlider()).toBeDisabled()
-    })
-  })
-
-  describe('User Interactions', () => {
-    it('should call onChange with id and value when InputNumber changes', async () => {
-      const user = userEvent.setup()
-      const StatefulParamItem = () => {
-        const [value, setValue] = useState(defaultProps.value)
-
-        return (
-          <ParamItem
-            {...defaultProps}
-            value={value}
-            onChange={(key: string, nextValue: number) => {
-              defaultProps.onChange(key, nextValue)
-              setValue(nextValue)
-            }}
-          />
-        )
-      }
-
-      render(<StatefulParamItem />)
-      const input = screen.getByRole('textbox')
-
-      await user.clear(input)
-      await user.type(input, '0.8')
-
-      expect(defaultProps.onChange).toHaveBeenLastCalledWith('test_param', 0.8)
-    })
-
-    it('should allow users to replace the minimum value with a multi-digit value', async () => {
-      const user = userEvent.setup()
-      const StatefulParamItem = () => {
-        const [value, setValue] = useState(1)
-
-        return (
-          <ParamItem
-            {...defaultProps}
-            value={value}
-            min={1}
-            max={100}
-            onChange={(key: string, nextValue: number) => {
-              defaultProps.onChange(key, nextValue)
-              setValue(nextValue)
-            }}
-          />
-        )
-      }
-
-      render(<StatefulParamItem />)
-
-      const input = screen.getByRole('textbox')
-      await user.clear(input)
-
-      expect(input).toHaveValue('')
-      expect(defaultProps.onChange).not.toHaveBeenCalled()
-
-      await user.type(input, '20')
-
-      expect(input).toHaveValue('20')
-      expect(defaultProps.onChange).toHaveBeenLastCalledWith('test_param', 20)
-      expect(getSlider()).toHaveAttribute('aria-valuenow', '20')
-    })
-
-    it('should clamp out-of-range text edits before updating state', async () => {
-      const user = userEvent.setup()
-      const StatefulParamItem = () => {
-        const [value, setValue] = useState(defaultProps.value)
-
-        return (
-          <ParamItem
-            {...defaultProps}
-            value={value}
-            onChange={(key: string, nextValue: number) => {
-              defaultProps.onChange(key, nextValue)
-              setValue(nextValue)
-            }}
-          />
-        )
-      }
-
-      render(<StatefulParamItem />)
-
-      const input = screen.getByRole('textbox')
-      await user.clear(input)
-      await user.type(input, '1.5')
-
-      expect(defaultProps.onChange).toHaveBeenLastCalledWith('test_param', 1)
-      expect(getSlider()).toHaveAttribute('aria-valuenow', '100')
-    })
-
-    it('should pass scaled value to slider when max < 5', () => {
-      render(<ParamItem {...defaultProps} value={0.5} />)
-      const slider = getSlider()
-
-      // When max < 5, slider value = value * 100 = 50
-      expect(slider).toHaveAttribute('aria-valuenow', '50')
-      expect(slider).toHaveAttribute('max', '100')
-    })
-
-    it('should pass raw value to slider when max >= 5', () => {
-      render(<ParamItem {...defaultProps} value={5} max={10} />)
-      const slider = getSlider()
-
-      // When max >= 5, slider value = value = 5
-      expect(slider).toHaveAttribute('aria-valuenow', '5')
-      expect(slider).toHaveAttribute('max', '10')
-    })
-
-    it('should call onSwitchChange with id and value when switch is toggled', async () => {
-      const user = userEvent.setup()
-      const onSwitchChange = vi.fn()
-      render(<ParamItem {...defaultProps} hasSwitch onSwitchChange={onSwitchChange} />)
-
-      await user.click(screen.getByRole('switch'))
-
-      expect(onSwitchChange).toHaveBeenCalledWith('test_param', false)
-    })
-
-    it('should call onChange with id when increment button is clicked', async () => {
-      const user = userEvent.setup()
-      render(<ParamItem {...defaultProps} value={0.5} step={0.1} />)
-      const incrementBtn = screen.getByRole('button', { name: /increment/i })
-
-      await user.click(incrementBtn)
-
-      // step=0.1, so 0.5 + 0.1 = 0.6, clamped to [0,1] → 0.6
-      expect(defaultProps.onChange).toHaveBeenCalledWith('test_param', 0.6)
-    })
-  })
-})
diff --git a/web/app/components/base/param-item/__tests__/param-item-example.tsx b/web/app/components/base/param-item/__tests__/param-item-example.tsx
new file mode 100644
index 00000000000..d6c145abfbf
--- /dev/null
+++ b/web/app/components/base/param-item/__tests__/param-item-example.tsx
@@ -0,0 +1,30 @@
+import type { ComponentProps } from 'react'
+import { useState } from 'react'
+import ParamItem from '..'
+
+type Props = Omit<
+  Partial<ComponentProps<typeof ParamItem>>,
+  'id' | 'name' | 'onChange' | 'onSwitchChange'
+>
+
+// A caller applies the public value/key payloads; no owner transformation is copied here.
+export function ParamItemExample({ value = 0.5, enable = true, max = 1, ...props }: Props) {
+  const [values, setValues] = useState({ test_param: value })
+  const [enabled, setEnabled] = useState({ test_param: enable })
+  return (
+    <>
+      <ParamItem
+        {...props}
+        id="test_param"
+        name="Test Param"
+        max={max}
+        value={values.test_param}
+        enable={enabled.test_param}
+        onChange={(key, next) => setValues((previous) => ({ ...previous, [key]: next }))}
+        onSwitchChange={(key, next) => setEnabled((previous) => ({ ...previous, [key]: next }))}
+      />
+      <output aria-label="Saved parameters">{JSON.stringify(values)}</output>
+      <output aria-label="Enabled parameters">{JSON.stringify(enabled)}</output>
+    </>
+  )
+}
diff --git a/web/app/components/base/param-item/__tests__/score-threshold-item.browser.spec.tsx b/web/app/components/base/param-item/__tests__/score-threshold-item.browser.spec.tsx
new file mode 100644
index 00000000000..b6e63f0884b
--- /dev/null
+++ b/web/app/components/base/param-item/__tests__/score-threshold-item.browser.spec.tsx
@@ -0,0 +1,71 @@
+import { useState } from 'react'
+import { page, userEvent } from 'vite-plus/test/browser'
+import { render } from 'vitest-browser-react'
+import ScoreThresholdItem from '../score-threshold-item'
+
+beforeEach(async () => {
+  await page.viewport(800, 600)
+})
+
+it.each([
+  [undefined, '0.7'],
+  [-0.1, '0'],
+  [1.5, '1'],
+  [0.556, '0.56'],
+])('normalizes configured threshold %s to %s in both editors', async (value, expected) => {
+  await render(<ScoreThresholdItem value={value} enable onChange={vi.fn()} />)
+  await expect
+    .element(page.getByRole('textbox', { name: 'appDebug.datasetConfig.score_threshold' }))
+    .toHaveValue(expected)
+  await expect
+    .element(page.getByRole('slider', { name: 'appDebug.datasetConfig.score_threshold' }))
+    .toHaveAttribute('aria-valuetext', expected)
+})
+
+it('saves threshold edits in hundredths and makes both editors unavailable when switched off', async () => {
+  function Settings() {
+    const [values, setValues] = useState({ score_threshold: 0.5 })
+    const [enabled, setEnabled] = useState({ score_threshold: true })
+    return (
+      <>
+        <ScoreThresholdItem
+          value={values.score_threshold}
+          enable={enabled.score_threshold}
+          hasSwitch
+          onChange={(key, next) => setValues((previous) => ({ ...previous, [key]: next }))}
+          onSwitchChange={(key, next) => setEnabled((previous) => ({ ...previous, [key]: next }))}
+        />
+        <output aria-label="Saved parameters">{JSON.stringify(values)}</output>
+        <output aria-label="Enabled parameters">{JSON.stringify(enabled)}</output>
+      </>
+    )
+  }
+  await render(<Settings />)
+  const name = 'appDebug.datasetConfig.score_threshold'
+  const input = page.getByRole('textbox', { name })
+  const slider = page.getByRole('slider', { name })
+  const saved = page.getByRole('status', { name: 'Saved parameters' })
+  await page.getByRole('button', { name: 'Increment value' }).click()
+  await expect.element(input).toHaveValue('0.51')
+  await expect.element(slider).toHaveAttribute('aria-valuetext', '0.51')
+  await expect.element(saved).toHaveTextContent('{"score_threshold":0.51}')
+  await input.clear()
+  await userEvent.keyboard('0.55')
+  await expect.element(input).toHaveValue('0.55')
+  await expect.element(slider).toHaveAttribute('aria-valuetext', '0.55')
+  await expect.element(saved).toHaveTextContent('{"score_threshold":0.55}')
+  // Return through the real tab order rather than imperatively focusing the switch.
+  await userEvent.tab({ shift: true })
+  await expect.element(page.getByRole('button', { name })).toHaveFocus()
+  await userEvent.tab({ shift: true })
+  const toggle = page.getByRole('switch', { name })
+  await expect.element(toggle).toHaveFocus()
+  await userEvent.keyboard(' ')
+  await expect.element(toggle).not.toBeChecked()
+  await expect
+    .element(page.getByRole('status', { name: 'Enabled parameters' }))
+    .toHaveTextContent('{"score_threshold":false}')
+  await expect.element(input).toBeDisabled()
+  await expect.element(slider).toBeDisabled()
+  await expect.element(saved).toHaveTextContent('{"score_threshold":0.55}')
+})
diff --git a/web/app/components/base/param-item/__tests__/score-threshold-item.spec.tsx b/web/app/components/base/param-item/__tests__/score-threshold-item.spec.tsx
deleted file mode 100644
index 5abfe4c5d40..00000000000
--- a/web/app/components/base/param-item/__tests__/score-threshold-item.spec.tsx
+++ /dev/null
@@ -1,55 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import userEvent from '@testing-library/user-event'
-import { useState } from 'react'
-import ScoreThresholdItem from '../score-threshold-item'
-
-it.each([
-  [undefined, '0.7'],
-  [-0.1, '0'],
-  [1.5, '1'],
-  [0.556, '0.56'],
-])('normalizes configured threshold %s to %s', (value, expected) => {
-  render(<ScoreThresholdItem value={value} enable onChange={vi.fn()} />)
-  expect(screen.getByRole('textbox')).toHaveValue(expected)
-})
-
-it('edits the score threshold in hundredths and disables its controls when switched off', async () => {
-  const user = userEvent.setup()
-  const onChange = vi.fn()
-  const onSwitchChange = vi.fn()
-  function Settings() {
-    const [value, setValue] = useState(0.5)
-    const [enable, setEnable] = useState(true)
-    return (
-      <ScoreThresholdItem
-        value={value}
-        enable={enable}
-        hasSwitch
-        onChange={(key, next) => {
-          onChange(key, next)
-          setValue(next)
-        }}
-        onSwitchChange={(key, next) => {
-          onSwitchChange(key, next)
-          setEnable(next)
-        }}
-      />
-    )
-  }
-  render(<Settings />)
-  const input = screen.getByRole('textbox')
-  await user.click(screen.getByRole('button', { name: /increment/i }))
-  expect(input).toHaveValue('0.51')
-  expect(onChange).toHaveBeenLastCalledWith('score_threshold', 0.51)
-  await user.clear(input)
-  await user.type(input, '0.55')
-  expect(onChange).toHaveBeenLastCalledWith('score_threshold', 0.55)
-  await user.click(screen.getByRole('switch'))
-  expect(onSwitchChange).toHaveBeenLastCalledWith('score_threshold', false)
-  expect(input).toBeDisabled()
-  expect(
-    screen.getByLabelText('appDebug.datasetConfig.score_threshold', {
-      selector: 'input[type="range"]',
-    }),
-  ).toBeDisabled()
-})
diff --git a/web/app/components/base/param-item/__tests__/top-k-item.browser.spec.tsx b/web/app/components/base/param-item/__tests__/top-k-item.browser.spec.tsx
new file mode 100644
index 00000000000..be912fa3e97
--- /dev/null
+++ b/web/app/components/base/param-item/__tests__/top-k-item.browser.spec.tsx
@@ -0,0 +1,80 @@
+import { useState } from 'react'
+import { page, userEvent } from 'vite-plus/test/browser'
+import { render } from 'vitest-browser-react'
+import TopKItem from '../top-k-item'
+
+vi.mock('@/env', () => ({ env: { NEXT_PUBLIC_TOP_K_MAX_VALUE: 10 } }))
+
+beforeEach(async () => {
+  await page.viewport(800, 600)
+})
+
+function Settings({ max }: { max?: number }) {
+  const [values, setValues] = useState({ top_k: 2 })
+  return (
+    <>
+      <TopKItem
+        enable
+        value={values.top_k}
+        max={max}
+        onChange={(key, next) => setValues((previous) => ({ ...previous, [key]: next }))}
+      />
+      <output aria-label="Saved parameters">{JSON.stringify(values)}</output>
+    </>
+  )
+}
+
+it('keeps numeric edits and native slider keys synchronized within configured top-k bounds', async () => {
+  await render(<Settings />)
+  const input = page.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' })
+  const slider = page.getByRole('slider', { name: 'appDebug.datasetConfig.top_k' })
+  const saved = page.getByRole('status', { name: 'Saved parameters' })
+  await page.getByRole('button', { name: 'Increment value' }).click()
+  await expect.element(input).toHaveValue('3')
+  await expect.element(slider).toHaveValue('3')
+  await expect.element(saved).toHaveTextContent('{"top_k":3}')
+  await input.click()
+  await userEvent.tab()
+  await expect.element(slider).toHaveFocus()
+  await userEvent.keyboard('{End}')
+  await expect.element(input).toHaveValue('10')
+  await expect.element(saved).toHaveTextContent('{"top_k":10}')
+  await userEvent.keyboard('{ArrowRight}')
+  await expect.element(input).toHaveValue('10')
+  await expect.element(saved).toHaveTextContent('{"top_k":10}')
+  await userEvent.keyboard('{Home}')
+  await expect.element(input).toHaveValue('1')
+  await expect.element(saved).toHaveTextContent('{"top_k":1}')
+  await userEvent.keyboard('{ArrowLeft}')
+  await expect.element(input).toHaveValue('1')
+  await expect.element(saved).toHaveTextContent('{"top_k":1}')
+})
+
+it.each([
+  { enable: false, disabled: false },
+  { enable: true, disabled: true },
+])('makes both top-k editors unavailable with %j', async (props) => {
+  await render(<TopKItem {...props} value={2} onChange={vi.fn()} />)
+  await expect
+    .element(page.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' }))
+    .toBeDisabled()
+  await expect
+    .element(page.getByRole('slider', { name: 'appDebug.datasetConfig.top_k' }))
+    .toBeDisabled()
+})
+
+it('applies a feature-specific maximum to native slider edits and the saved top-k', async () => {
+  await render(<Settings max={100} />)
+  const slider = page.getByRole('slider', { name: 'appDebug.datasetConfig.top_k' })
+  await page.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' }).click()
+  await userEvent.tab()
+  await expect.element(slider).toHaveFocus()
+  await userEvent.keyboard('{End}')
+  await expect.element(slider).toHaveValue('100')
+  await expect
+    .element(page.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' }))
+    .toHaveValue('100')
+  await expect
+    .element(page.getByRole('status', { name: 'Saved parameters' }))
+    .toHaveTextContent('{"top_k":100}')
+})
diff --git a/web/app/components/base/param-item/__tests__/top-k-item.spec.tsx b/web/app/components/base/param-item/__tests__/top-k-item.spec.tsx
deleted file mode 100644
index b2f47fd5cc4..00000000000
--- a/web/app/components/base/param-item/__tests__/top-k-item.spec.tsx
+++ /dev/null
@@ -1,62 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import userEvent from '@testing-library/user-event'
-import { useState } from 'react'
-import TopKItem from '../top-k-item'
-
-vi.mock('@/env', () => ({ env: { NEXT_PUBLIC_TOP_K_MAX_VALUE: 10 } }))
-
-it('keeps the numeric field and slider synchronized within the configured top-k bounds', async () => {
-  const user = userEvent.setup()
-  const onChange = vi.fn()
-  function Harness() {
-    const [value, setValue] = useState(2)
-    return (
-      <TopKItem
-        enable
-        value={value}
-        onChange={(key, next) => {
-          onChange(key, next)
-          setValue(next)
-        }}
-      />
-    )
-  }
-  render(<Harness />)
-  const input = screen.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' })
-  const slider = screen.getByLabelText('appDebug.datasetConfig.top_k', {
-    selector: 'input[type="range"]',
-  })
-  await user.click(screen.getByRole('button', { name: /increment/i }))
-  expect(input).toHaveValue('3')
-  expect(slider).toHaveValue('3')
-  slider.focus()
-  await user.keyboard('{End}{ArrowRight}')
-  expect(input).toHaveValue('10')
-  expect(onChange).toHaveBeenLastCalledWith('top_k', 10)
-  await user.keyboard('{Home}{ArrowLeft}')
-  expect(input).toHaveValue('1')
-  expect(onChange).toHaveBeenLastCalledWith('top_k', 1)
-})
-
-it.each([
-  { enable: false, disabled: false },
-  { enable: true, disabled: true },
-])('prevents edits with %j', async (props) => {
-  const user = userEvent.setup()
-  const onChange = vi.fn()
-  render(<TopKItem {...props} value={2} onChange={onChange} />)
-  const input = screen.getByRole('textbox', { name: 'appDebug.datasetConfig.top_k' })
-  expect(input).toBeDisabled()
-  expect(
-    screen.getByLabelText('appDebug.datasetConfig.top_k', { selector: 'input[type="range"]' }),
-  ).toBeDisabled()
-  await user.type(input, '9')
-  expect(onChange).not.toHaveBeenCalled()
-})
-
-it('allows a feature-specific maximum', () => {
-  render(<TopKItem enable value={2} max={100} onChange={vi.fn()} />)
-  expect(
-    screen.getByLabelText('appDebug.datasetConfig.top_k', { selector: 'input[type="range"]' }),
-  ).toHaveAttribute('max', '100')
-})