fix: validate gps-summary path against every library

The /photos/gps-summary handler validated the incoming path against
the primary library's root with new_file=false, which requires the
path to exist on disk. For a viewer opened on a file from a
non-primary library, tapping the GPS link produced activePath =
<folder from lib 2>, the primary-only check failed, and the server
400'd — so the map came up empty.

Validation here is purely a traversal guard (the DAO does a prefix
LIKE against rel_path), so we now accept the path as long as any
configured library can resolve it without escaping its root.

Also applies cargo fmt drift on files touched this session.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/video/actors.rs

@@ -526,9 +526,7 @@ impl PreviewClipGenerator {
     fn relativize(&self, video_path: &str) -> String {
         for lib in &self.libraries {
             if let Some(stripped) = video_path.strip_prefix(&lib.root_path) {
-                return stripped
-                    .trim_start_matches(['/', '\\'])
-                    .replace('\\', "/");
+                return stripped.trim_start_matches(['/', '\\']).replace('\\', "/");
             }
         }
         video_path