Passing Day.js instance to Moment returns current date instead of original value

**Describe the bug**
When a Day.js instance is passed directly to Moment (`moment(dayjsValue)`), the resulting Moment date becomes the current date instead of the Day.js date for some inputs.

In my case, this caused a CSV export range bug: selecting `2026-03-01` to `2026-03-19` ended up sending `from` as `2026-03-19` (today), so only today's records were exported.

**Expected behavior**
`moment(dayjs('2026-03-01'))` should represent `2026-03-01`, not the current date.

**Actual behavior**
`moment(dayjs('2026-03-01')).format()` returns `2026-03-19...` (current day in my environment).

**Minimal reproduction**
```js
const moment = require('moment')
const dayjs = require('dayjs')

const d = dayjs('2026-03-01')

console.log('dayjs:', d.format()) // 2026-03-01T00:00:00+09:00
console.log('moment(dayjs):', moment(d).format()) // 2026-03-19T00:00:00+09:00 (unexpected)
console.log('moment(dayjs.toDate()):', moment(d.toDate()).format()) // 2026-03-01T00:00:00+09:00 (expected)
```
Day.js Version: 1.11.19
OS: Linux
Browser: N/A (Node.js reproduction)
Node.js: v24.0.0
Moment Version: 2.30.1
Time zone: Asia/Tokyo (GMT+09:00)

Start with the Node.js minimal reproduction in the issue and compare moment(dayjsValue) with moment(dayjsValue.toDate()). Trace how the Day.js instance is passed into Moment for the affected inputs. Done means the direct conversion preserves the original date and a regression test covers the reported case.

Written by the indexing model from the issue text.