fix(techdemo): keep work ids typed

Complete the InteractionForm::parse migration for techdemo work updates so typed ids stay typed instead of being reparsed inside the helper.

req: form/004

req: dx/003

req: examples/003

examples/techdemo/src/main.rs

@@ -404,8 +404,8 @@ fn registry(shared: Arc<Shared>) -> impl DispatchRegistry {
         })
 }
 
-fn update_work(demo: &mut DemoState, id: Option<&str>, update: impl FnOnce(&mut WorkItem)) -> Option<String> {
+fn update_work(demo: &mut DemoState, id: Option<u64>, update: impl FnOnce(&mut WorkItem)) -> Option<String> {
-    let id = id.and_then(|value| value.parse::<u64>().ok())?;
+    let id = id?;
     let item = demo.work.iter_mut().find(|item| item.id == id)?;
     let title = item.title.clone();
     update(item);