style(server): cargo fmt for trusted-proxy IP extractor (CI green)

5d5cd26 compiles + passes clippy -D warnings + all 45 tests on the build host;
only cargo fmt --check failed on one reflowed method chain in ip_extract.rs.
No logic change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/src/utils/ip_extract.rs

@@ -210,7 +210,11 @@ fn xff_rightmost_untrusted(headers: &HeaderMap, trusted: &TrustedProxies) -> Opt
 
     // Walk right-to-left, skipping trusted proxies, and return the first client
     // address (the hop the outermost trusted proxy actually saw).
-    tokens.iter().rev().find(|ip| !trusted.is_trusted(ip)).copied()
+    tokens
+        .iter()
+        .rev()
+        .find(|ip| !trusted.is_trusted(ip))
+        .copied()
 }
 
 #[cfg(test)]