feat(api,web): remove a movie, files optional

`DELETE /api/movies/{id}` took the row and left the files, and no
surface exposed it. It now accepts `delete_files`, which unlinks the
title's §7.4 folder — atomic, so sidecars go with the feature. Targets
come from `media_files`, never from re-deriving the folder name, and a
path outside its root is never touched. The torrent is untouched (§7.3):
it keeps seeding and the reaper owns it.

The release deck grows a quiet REMOVE control opening one inline
confirmation: file count, size and folder first, then a delete-files
toggle that starts off, then what the choice costs.

Closes #104

crates/arr-api/src/lib.rs

@@ -23,7 +23,8 @@ use utoipa_scalar::{Scalar, Servable};
 
 pub use health::{Check, Health, HealthReport, Status};
 pub use movies::{
-    Accepted, AttentionQueues, CreateMovie, ErrorBody, Movie, MovieFile, Release, UpdateMovie,
+    Accepted, AttentionQueues, CreateMovie, DeleteMovieQuery, ErrorBody, Movie, MovieFile, Release,
+    UpdateMovie,
 };
 pub use owners::{CreateOwner, Owner, UpdateOwner};
 pub use roots::Root;