fix: plusieurs retours UX/UI (#58)

| Numéro du ticket | Titre du ticket |
|------------------|-----------------|
|                  |                 |

## Description de la PR

## Modification du .env

## Check list

- [ ] Pas de régression
- [ ] TU/TI/TF rédigée
- [ ] TU/TI/TF OK
- [ ] CHANGELOG modifié

---------

Co-authored-by: THOLOT DECHENE Matthieu <matthieu@yuno.malio.fr>
Co-authored-by: matthieu <matthieu@yuno.malio.fr>
Reviewed-on: #58
Co-authored-by: tristan <tristan@yuno.malio.fr>
Co-committed-by: tristan <tristan@yuno.malio.fr>

app/components/malio/select/Select.test.ts

@@ -207,4 +207,70 @@ describe('MalioSelect', () => {
     expect(wrapper.find('p.text-m-success').exists()).toBe(false)
     expect(wrapper.get('p.text-m-danger').text()).toBe('Selection error')
   })
+
+  it('shows muted chevron color when empty and closed', () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: null, options},
+    })
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-m-muted')
+  })
+
+  it('shows primary chevron color when open', async () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: null, options},
+    })
+
+    await wrapper.get('button').trigger('click')
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-m-primary')
+  })
+
+  it('shows black chevron color when an option is selected and closed', () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: 'fr', options},
+    })
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-black')
+  })
+
+  it('shows muted chevron color when disabled', () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: 'fr', options, disabled: true},
+    })
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-m-muted')
+  })
+
+  it('shows danger chevron color on error even when open', async () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: null, options, error: 'Selection error'},
+    })
+
+    await wrapper.get('button').trigger('click')
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-m-danger')
+  })
+
+  it('shows success chevron color on success', () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: null, options, success: 'OK'},
+    })
+
+    expect(wrapper.get('[data-test="chevron"]').classes()).toContain('text-m-success')
+  })
+
+  it('keeps the bottom border allocation when open downward (transparent, not zero)', async () => {
+    const wrapper = mount(SelectForTest, {
+      props: {modelValue: null, options},
+    })
+
+    await wrapper.get('button').trigger('click')
+
+    const buttonClasses = wrapper.get('button').classes()
+    // !border-b-0 would shrink the bottom border to 0px and grow content area by 1px;
+    // !border-b-transparent keeps the 1px allocation but hides the line
+    expect(buttonClasses).not.toContain('!border-b-0')
+    expect(buttonClasses).toContain('!border-b-transparent')
+  })
 })