style: apply current rustfmt to the tree

A newer rustfmt wraps over-long match arms and call expressions that the
version main was last formatted with left on one line. Pure formatting,
no semantic change — split out so the friends-list feature commits stay
focused on real changes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/gui/child.rs

@@ -261,12 +261,20 @@ mod tests {
     #[test]
     fn capture_state_round_trips() {
         assert!(matches!(
-            parse(Event::Capture { state: EmitState::Started }),
-            ChildEvent::Capture { state: CaptureState::Started }
+            parse(Event::Capture {
+                state: EmitState::Started
+            }),
+            ChildEvent::Capture {
+                state: CaptureState::Started
+            }
         ));
         assert!(matches!(
-            parse(Event::Capture { state: EmitState::Stopped }),
-            ChildEvent::Capture { state: CaptureState::Stopped }
+            parse(Event::Capture {
+                state: EmitState::Stopped
+            }),
+            ChildEvent::Capture {
+                state: CaptureState::Stopped
+            }
         ));
     }