Remove list format and convert to heading when Header button pressed on list item

[Copilot]

Pressing the Heading button while the cursor was inside a list item did nothing useful — headings can't exist inside list nodes in Tiptap, so the command silently failed.

Changes

editorCommands.ts — cycleHeading()

Added list-type detection before the normal heading cycle. When the cursor is in a list item, the list is unwrapped first, then H1 is applied:

• bulletList / orderedList: uses toggleBulletList() / toggleOrderedList() to lift the item to a paragraph, then chains setHeading({ level: 1 })
• taskList: uses liftListItem("taskItem") directly (no built-in toggle command for custom task list nodes), then chains setHeading({ level: 1 })

if (editor.isActive("bulletList")) {
  editor.chain().focus().toggleBulletList().setHeading({ level: 1 }).run();
  return;
}
// orderedList and taskList handled similarly…

Toolbar.tsx — Heading button tooltip

Added a "Heading: List → H1" tooltip state for when the cursor is inside any list, consistent with the existing H1→H2→H3→Normal tooltip progression.