fix(admin): datetime popover clock, unsaved confirm, inferred list dates

BM UAT on v0.1.1 showed a date-only calendar for datetime fields, a stuck discard dialog, and raw ISO timestamps when columns.yaml omitted type. The picker now edits time in the popover, confirm sits above the calendar, and omitted time.Time / Date / TimeOfDay columns compile as datetime / date / time.

Co-authored-by: Cursor <cursoragent@cursor.com>

admin/tests/form/DatepickerField.test.ts

@@ -124,6 +124,31 @@ describe('calendar popover (backstop 1)', () => {
     wrapper.unmount()
   })
 
+  it('shows a time picker in the datetime popover and keeps the popover open after a day click', async () => {
+    const wrapper = mountField(field(), '2026-10-02T10:30:00Z')
+    await wrapper.find('[data-action="open-calendar"]').trigger('click')
+    await flushPromises()
+    const popover = document.body.querySelector<HTMLElement>('[data-datepicker-calendar]')
+    expect(popover).not.toBeNull()
+    const clock = popover!.querySelector<HTMLElement>('[data-datepicker-time]')
+    expect(clock).not.toBeNull()
+    expect(clock!.querySelector('[data-reka-time-field-segment="hour"]')?.textContent).toBe('12')
+    expect(clock!.querySelector('[data-reka-time-field-segment="minute"]')?.textContent).toBe('30')
+    const day = Array.from(popover!.querySelectorAll<HTMLElement>('[data-reka-calendar-cell-trigger]')).find(
+      (el) => el.textContent?.trim() === '3' && !el.hasAttribute('data-outside-view'),
+    )
+    day?.click()
+    await flushPromises()
+    expect(document.body.querySelector('[data-datepicker-calendar]')).not.toBeNull()
+    expect(emitted(wrapper).at(-1)).toBe('2026-10-03T10:30:00Z')
+    const minute = clock!.querySelector<HTMLElement>('[data-reka-time-field-segment="minute"]')!
+    minute.focus()
+    keydown(minute, 'ArrowUp')
+    await flushPromises()
+    expect(emitted(wrapper).at(-1)).toBe('2026-10-03T10:31:00Z')
+    wrapper.unmount()
+  })
+
   it('starts the week on the field firstDay, else on the locale first day', async () => {
     const heads = async (f: FormField) => {
       const wrapper = mountField(f, '2026-10-10')