Take rustfmt's defaults

The code was hand-formatted -- close to rustfmt's output but not it, mostly
in keeping chains and call arguments on one line where the formatter would
break them. That is a per-line decision every future change has to make
again, and reproducing it would mean a config whose only job is to preserve
how the code already looks.

So this is `cargo fmt` at its defaults, with no rustfmt.toml, which is
where the sibling dev-updater checkout already sits: it is clean at the
defaults today, so the two repos now agree on layout without either of them
configuring it.

Formatting only -- no behaviour, no renames, nothing reordered. Verified
after: cargo test (35 pass), cargo clippy --all-targets clean, cargo fmt
--check clean.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw

server/src/media.rs

@@ -45,7 +45,10 @@ mod tests {
     fn the_two_directions_agree() {
         for (media_type, extension) in IMAGE_TYPES {
             assert_eq!(extension_for(media_type), Some(extension));
-            assert_eq!(media_type_for(&format!("abc123.{extension}")), Some(media_type));
+            assert_eq!(
+                media_type_for(&format!("abc123.{extension}")),
+                Some(media_type)
+            );
         }
     }