Date-valued window arithmetic appends a zero-time suffix

## What happened

Dolt exhibits this behavior: date-valued window arithmetic appends a zero-time suffix. Not sure whether this is intended.

## Environment

Dolt latest `main` commit `59fb843bf6a4b653d7c8b6d997a603b10cf279d9` (`dolt version 2.2.3`, ICU build).

## How to reproduce

```sql
CREATE TABLE t(id INT PRIMARY KEY, d DATE);
INSERT INTO t VALUES (1, '2024-01-01'), (2, '2024-01-02');

SELECT id,
FIRST_VALUE(d) OVER (ORDER BY id) + 0 AS actual
FROM t
ORDER BY id;
```

## Expected result

MySQL 8.0.43 fresh run:

```text
id actual
1 20240101
2 20240101
```

MySQL's numeric context converts a DATE to its exact `YYYYMMDD` integer.

## Actual result

```text
id actual
1 20240101000000
2 20240101000000
```

The 14-digit datetime form is returned on every fresh replay. Related exact integer operators (`-`, `DIV`, and `MOD`) exhibit the same conversion, while the `+ 0` witness is the minimal representative.

Run the supplied SQL reproduction on Dolt and compare its DATE arithmetic with the expected MySQL result. Trace the numeric conversion used by window expressions and the related -, DIV, and MOD operators; done means + 0 returns the exact YYYYMMDD value without a zero-time suffix.

Written by the indexing model from the issue text.