Say on the import page where the photographs end up

Three lint findings and the gap the third one was pointing at.

`Context::library_label` was dead: the page named the folder on this machine
and said nothing at all about the server, which is half of what the Import
button commits to and the half that takes minutes rather than seconds. It now
names both, and states the order — copied and verified here first, then
uploaded (FR-NC-7b) — beside the destinations rather than beside the button,
because someone watching a slow upload needs to already know the photographs
are safe on disk.

The label is cached when the page opens rather than read in `render`: reaching
it goes through the context closure to the account, and `render` runs on every
keystroke.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

platform/dr-plat/src/volumes.rs

@@ -83,7 +83,7 @@ fn platform_volumes() -> Vec<Volume> {
     };
     parse_mounts(&table)
         .into_iter()
-        .filter(|m| is_candidate(m))
+        .filter(is_candidate)
         .map(|m| {
             let removable = device_is_removable(&m.device).unwrap_or(false)
                 // A desktop that automounts under /run/media or /media has