feat(gui,fuse): delete photos from the gallery and notice remote deletions

The gallery could show photos and nothing else: a photo deleted on the phone
stayed on the page for minutes, and a photo you wanted gone had to be deleted
on another device. Both are now handled here.

Deleting needs a uid-addressed request, because `Request::Delete` takes a
mountpoint path and the photos volume is not in the FUSE mount. `TrashNodes`
trashes through the SDK and answers per-uid outcomes, so a partial failure is
reportable; the daemon then drops those rows with `Db::photos_delete`, album
membership included, rather than leaving the gallery to wait for the next
timeline refresh. The GUI removes the tiles immediately with an Undo toast and
puts back anything the server refused — the photos are in Proton's trash and
stay recoverable there either way. Selection is Ctrl/Shift+click, the Select
toggle or Delete in the lightbox.

Remote deletions arrive on their own now. The Drive volume and the photos
volume have separate event streams, so the photos volume gets its own poller
and its own cursor. Trash and delete events remove rows; anything else only
marks the timeline stale, because there is no inode space to converge on this
volume. With the timeline TTL down to 60 s and an explicit Refresh that waits
for the server instead of only clearing the freshness stamp, a photo deleted
elsewhere leaves the grid in about ten seconds.

crates/pdfs-core/src/control.rs

@@ -93,6 +93,13 @@ pub enum Request {
     /// already cached (one batched round-trip) and replying with their on-disk
     /// paths. Keep the batch small — it is served on demand, as tiles scroll in.
     PhotoThumbs { uids: Vec<String> },
+    /// Trash photos by node uid, answered with [`Response::Trashed`].
+    ///
+    /// Uid-addressed rather than path-addressed because the photos volume is not
+    /// part of the FUSE mount: the gallery knows a photo only by its uid, and
+    /// [`Request::Delete`] has no path to take for it. The nodes land in Proton
+    /// trash, so this stays recoverable from the Trash page.
+    TrashNodes { uids: Vec<String> },
     /// Fetch thumbnails for ordinary Drive image files shown outside the Photos
     /// timeline. The modification time is the cache validity tag, so replacing
     /// an image can never reuse its previous revision's thumbnail.
@@ -1288,6 +1295,13 @@ fn default_photo_kind() -> PhotoKind {
     PhotoKind::Photo
 }
 
+/// One node a [`Request::TrashNodes`] batch could not trash, and why.
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct TrashFailure {
+    pub uid: String,
+    pub message: String,
+}
+
 /// One thumbnail in a [`Response::Thumbs`] batch.
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct PhotoThumb {
@@ -1587,6 +1601,14 @@ pub enum Response {
     PhotoMonths { months: Vec<PhotoMonth> },
     /// Thumbnails for a [`Request::PhotoThumbs`] batch.
     Thumbs { items: Vec<PhotoThumb> },
+    /// Per-node outcome of a [`Request::TrashNodes`] batch. Reported per uid
+    /// rather than as one verdict: the server answers each node separately, and
+    /// a front-end that removed all of them on a partial success would show a
+    /// photo as gone that is still there.
+    Trashed {
+        trashed: Vec<String>,
+        failed: Vec<TrashFailure>,
+    },
     /// A [`Request::FileThumbs`] generation is no longer current. This is
     /// retryable after reserving a fresh generation and must never be interpreted
     /// as a permanent "no thumbnail" verdict.
@@ -1925,6 +1947,36 @@ mod tests {
         assert!(items[0].name.is_empty());
     }
 
+    /// The gallery trashes by uid, and reports per-uid outcomes back: a partial
+    /// failure has to survive the wire so the GUI can put those tiles back.
+    #[test]
+    fn trash_requests_and_outcomes_roundtrip() {
+        let request = Request::TrashNodes {
+            uids: vec!["volume~first".into(), "volume~second".into()],
+        };
+        let line = serde_json::to_string(&request).unwrap();
+        assert!(!line.contains('\n'), "wire form must be a single line");
+        let decoded: Request = serde_json::from_str(&line).unwrap();
+        assert_eq!(line, serde_json::to_string(&decoded).unwrap());
+
+        let response = Response::Trashed {
+            trashed: vec!["volume~first".into()],
+            failed: vec![TrashFailure {
+                uid: "volume~second".into(),
+                message: "permission denied".into(),
+            }],
+        };
+        let line = serde_json::to_string(&response).unwrap();
+        let decoded: Response = serde_json::from_str(&line).unwrap();
+        let Response::Trashed { trashed, failed } = decoded else {
+            panic!("decoded the wrong response variant");
+        };
+        assert_eq!(trashed, ["volume~first"]);
+        assert_eq!(failed.len(), 1);
+        assert_eq!(failed[0].uid, "volume~second");
+        assert_eq!(failed[0].message, "permission denied");
+    }
+
     #[test]
     fn thumbnail_build_requests_and_progress_roundtrip() {
         let requests = [