fix: catch touying pauses in groups and syncs

src/core/setup.typ

@@ -1,12 +1,17 @@
 #import "draw/group.typ": render-end as grp-render-end
 #import "draw/hide.typ": render-end as hide-render-end
 #import "draw/sync.typ": render-end as sync-render-end
-#import "utils.typ": get-group-span, is-elmt
+#import "utils.typ": get-group-span, is-elmt, is-touying-pause
 #import "/src/participant.typ": _exists as par-exists, _par
 #import "/src/sequence.typ": _seq
 
 #let flatten-group(elmts, i) = {
   let group = elmts.at(i)
+  for elmt in group.elmts {
+    if is-touying-pause(elmt) {
+      panic("Cannot pause inside of a group yet")
+    }
+  }
   elmts.at(i) = group
   return (
     elmts.slice(0, i + 1) +
@@ -22,6 +27,11 @@
 
 #let flatten-sync(elmts, i) = {
   let sync = elmts.at(i)
+  for elmt in sync.elmts {
+    if is-touying-pause(elmt) {
+      panic("Cannot pause inside of a sync")
+    }
+  }
   elmts.at(i) = sync
   let start = sync
   start.remove("elmts")

src/core/utils.typ

@@ -10,6 +10,17 @@
   return true
 }
 
+#let is-touying-pause(elmt) = {
+  if type(elmt) != content or elmt.func() != metadata {
+    return false
+  }
+  let kind = elmt.value.at("kind", default: "")
+  if type(kind) != str {
+    return false
+  }
+  return kind.starts-with("touying-jump")
+}
+
 #let normalize-units(value) = {
   if type(value) == int or type(value) == float {
     return value
@@ -33,6 +44,12 @@
   let pars-i = get-participants-i(participants)
 
   for elmt in group.elmts {
+    if not is-elmt(elmt) {
+      if is-touying-pause(elmt) {
+        panic("Cannot pause inside of a group yet")
+      }
+      continue
+    }
     if elmt.type == "seq" {
       let i1 = pars-i.at(elmt.p1)
       let i2 = pars-i.at(elmt.p2)