feat(ui): render the scene sharing dialogs and bar from a store

createSceneDialog keeps its builder but publishes the dialog's lines,
fields, buttons and status to a scene sharing store; SceneDialog.vue,
teleported to the body from the scene panels view, draws the same modal
with the same styles and opens it with Cancel focused. The EDIT DETAILS /
SHARE SCENE bar is drawn by that view while sharing offers it. The status
directive is shared with Provider Settings, and the two QA scripts that
drove the old DOM read the new dialog.

src/ui/sceneControls.test.mjs

@@ -3,7 +3,6 @@ import assert from 'node:assert/strict';
 import { assertSameNode } from '../testSupport/domAssert.mjs';
 import { createStateChannel } from '../app/stateChannel.js';
 import { sceneElements } from './scenePresentation.js';
-import { mountSceneSharing } from './sceneSharing.js';
 import { setLocale } from '../i18n/index.js';
 import { installVueDom } from '../testSupport/vueDom.mjs';
 
@@ -585,74 +584,3 @@ test('Authoring PLAY uses the scene context, not the radio PLAY', (context) => {
     f.restore();
   }
 });
-
-test('The sharing row sits under SAVE & SHARE, after the file row', () => {
-  const saved = globalThis.document;
-  const node = (className = '') => {
-    const element = {
-      className,
-      children: [],
-      dataset: {},
-      parent: null,
-      addEventListener() {},
-      removeEventListener() {},
-      append(...items) {
-        for (const item of items) {
-          item.parent = element;
-          element.children.push(item);
-        }
-      },
-      appendChild(item) {
-        element.append(item);
-      },
-      after(item) {
-        const siblings = element.parent.children;
-        item.parent = element.parent;
-        siblings.splice(siblings.indexOf(element) + 1, 0, item);
-      },
-      remove() {
-        const siblings = element.parent?.children;
-        if (siblings) siblings.splice(siblings.indexOf(element), 1);
-      },
-      querySelector(selector) {
-        const name = selector.slice(1);
-        const walk = (at) => {
-          for (const child of at.children) {
-            if (child.className.split(' ').includes(name)) return child;
-            const found = walk(child);
-            if (found) return found;
-          }
-          return null;
-        };
-        return walk(element);
-      },
-    };
-    return element;
-  };
-  globalThis.document = { createElement: () => node() };
-  try {
-    const panel = node();
-    const inner = node('scene-panel-inner');
-    const fileRow = node('scene-controls scene-file-controls');
-    const status = node('scene-status');
-    panel.append(inner);
-    inner.append(fileRow, status);
-    const dispose = mountSceneSharing({ edit() {}, share() {} }, panel);
-    const bar = inner.children[1];
-    assert.equal(bar.className, 'scene-controls');
-    assertSameNode(inner.children[2], status);
-    assert.ok(bar.children.every((button) => button.title));
-    dispose();
-    assert.deepEqual(inner.children, [fileRow, status]);
-
-    // Without the file row, the bar still lands inside the panel.
-    const plain = node();
-    const plainInner = node('scene-panel-inner');
-    plain.append(plainInner);
-    mountSceneSharing({ edit() {}, share() {} }, plain)();
-    mountSceneSharing({ edit() {}, share() {} }, plain);
-    assert.equal(plainInner.children.length, 1);
-  } finally {
-    globalThis.document = saved;
-  }
-});