Address review: playable PLAY/NEXT, visible rename editor, accurate copy

- PLAY and NEXT continue into the following scenes, so they stay
  enabled while any scene in the project has a shot, not only the
  selected one.
- Renaming a shot drops the number and ellipsis so the editor is no
  longer hidden; qa-scene-controls checks a long rename stays visible.
- PLAY, NEXT, EDIT DETAILS and SHARE SCENE tooltips describe what the
  buttons do, translated in every shipped language.
- The primary actions and the file row keep a hover state.
- Docs: the EXPORT rename in DIRECTOR-SHARING and the playback button
  states in CURRENT-STATE are accurate.
- Test the voice "authoring" alias through set_panel_open.

src/ui/sceneControls.test.mjs

@@ -184,7 +184,16 @@ test('Authoring disables idle actions that would do nothing', () => {
     assert.equal(f.elements.update.disabled, true);
     assert.equal(f.elements.start.disabled, false);
 
+    // PLAY and NEXT run on into the following scenes, so an empty selected
+    // scene beside one with shots keeps them available.
     f.state.scenes[0].shots = [];
+    f.state.scenes.push({ id: 'scene-b', title: 'B', shots: [{ id: 'b1' }] });
+    f.owner.setButtons(false);
+    assert.equal(f.elements.start.disabled, false);
+    assert.equal(f.elements.next.disabled, false);
+    assert.equal(f.elements.update.disabled, true);
+
+    f.state.scenes.pop();
     f.owner.setButtons(false);
     assert.equal(f.elements.start.disabled, true);
     assert.equal(f.elements.next.disabled, true);