Mark a file the decoder cannot open, so the sweep stops fetching it

A decode failure in the face sweep was counted, logged at debug where
nobody saw it, and left unmarked — so the next pass fetched the same
file and failed the same way. For the 521 MB panorama behind rawler's
panic that was half a gigabyte per sweep, on a tablet. It is now marked
examined with nothing found and a zero edge, which is what a later "try
again with a better decoder" pass would select on, and the warning
names the file. The failure count is unchanged: it did fail.

ui/dr-ui/src/library.rs

@@ -4298,7 +4298,30 @@ pub fn spawn_face_sweep(
                             }
                         }
                         Err(e) => {
-                            log::debug!("face sweep: {}: {e}", req.path);
+                            // A file the decoder cannot open fails the same
+                            // way on every pass, and every pass fetched it
+                            // first: a 521 MB panorama the decoder refuses
+                            // was downloaded once per sweep, on a tablet,
+                            // and reported at debug level where nobody saw
+                            // it. It is marked examined with nothing found,
+                            // so the next pass does not fetch it again; the
+                            // zero edge is what says why, and is what a
+                            // later "try again with a better decoder" pass
+                            // would select on. The count still says it
+                            // failed, because it did.
+                            log::warn!("face sweep: {}: {e}", req.path);
+                            if let Err(e) = dr_catalog::faces::record_detections(
+                                catalog.connection(),
+                                dr_types::ImageId(req.image_id as u64),
+                                &model_id,
+                                0,
+                                &[],
+                            ) {
+                                log::warn!(
+                                    "face sweep: marking {} as unreadable: {e}",
+                                    req.image_id
+                                );
+                            }
                             lane_failed += 1;
                         }
                     }