Room specific "Show media in timeline" setting should also toggle Link Preview

### Your use case

#### What would you like to do?

When selecting "Always Hide" for the "Show media in timeline" Setting within the General Room Settings that should also disable the Link Preview for that room.

#### Why would you like to do it?

Prevent me from seeing Spam Pictures.

#### Current situation:

Currently it's possible to show a Users pictures even though Media is disabled:

(And yes, in that case it isn't Spam)

### Have you considered any alternatives?

An alternative could be a room specific Link Preview Setting. I actually would prefer that and i think in the past that existed? But given that there probably is some reason it got removed my proposal of tying it to the Media Setting seems more realistic.

### Additional context

_No response_

Start by locating the General Room Settings implementation and the existing "Show media in timeline" and Link Preview handling. Trace how the room-specific media setting is applied, then verify that choosing "Always Hide" also prevents link previews in that room without affecting other rooms.

Written by the indexing model from the issue text.