feat(examples): polish workout phone UI

Give the workout exemplar a durable gym-floor command-slate direction, serve focused CSS, keep the first viewport centered on one action, and extend the HTTP E2E to verify stylesheet delivery.

req: examples/001

req: local/001

req: local/003

req: host/002

examples/workout/src/lib.rs

@@ -667,8 +667,8 @@ mod tests {
         let html = render(&WorkoutState::demo()).to_string();
         assert!(html.contains("Now-first Workout Copilot"));
         assert!(html.contains("Complete set"));
-        assert!(html.contains("Export via browser/PWA share"));
-        assert!(html.contains("Request native haptic"));
+        assert!(html.contains("Share export"));
+        assert!(html.contains("Haptic"));
         assert!(!html.contains(&format!("<{}", "script")));
         assert!(!html.contains("querySelector"));
     }