Tag the SAF export path FR-EXP-10 only, not FR-PLAT-AND-1

saf.rs and the export path's SAF branch shipped tagged FR-PLAT-AND-1,
and the matrix counted the requirement as covered. Its subject is the
library — reached through SAF grants — and Android still reaches a
library over a Nextcloud account or a folder path. What the SAF code
does is give an album a folder on the tablet, which is FR-EXP-10.

outstanding.md said the figure overstated it and should be read with
this one subtracted; it now says the tags were narrowed, and coverage
reads 161 of 192.

ui/dr-ui/src/export.rs

@@ -213,7 +213,7 @@ pub fn place(
             if destination.trim().is_empty() {
                 return Err("No export folder is set. Choose an album to export to.".into());
             }
-            // TRACES: FR-EXP-10 | FR-PLAT-AND-1
+            // TRACES: FR-EXP-10
             // A SAF tree on Android: written through the provider, which may
             // rename on a collision, so the name it reports is the one kept.
             #[cfg(target_os = "android")]