[Bug]: Working with .sync-exclude.lst is EXTREMELY DANGEROUS!

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I've searched it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

There were some synchronization problems with a specific folder, so I thought to temporarily exclude that folder from syncing.

Now I wanted to undo the exclusion.. so I simply removend that line.

Server in (over)load and that triggered my suspicions.. Of that folder half of the files were already deleted.. no less then 50.000 files deleted !!

Via OCC I restored that.. but what ever I do.. it's impossible to get this fixed in a decent way?!

### Steps to reproduce

- see above

### Expected behavior

At the **very least** a massive warning when "testing / working" with exclusions!

Even better would be the option when changing filters I would be asked the question:

**Filter(s) changed:**
[ checkbox ] **download** files from server when not found locally
[ checkbox ] **delete** files on server when not found locally

Before continuing one MUST choose one or the other.. That way the user is made aware of the choice that needs to be made.

This is **BEYOND** important. Now file loss is a more than small risk!

### Which files are affected by this bug

ALL excluded and then not excluded

### Operating system

Windows

### Which version of the operating system you are running.

Windows 10

### Package

Official Linux AppImage

### Nextcloud Server version

30

### Nextcloud Desktop Client version

3.16.3

### Is this bug present after an update or on a fresh install?

Updated from a minor version (ex. 3.4.2 to 3.4.4)

### Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

### Are you using an external user-backend?

- [ ] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

```shell

```

### Additional info

_No response_