feat(ui): render application templates as Vue views mounted before wiring

Templates listed in build/applicationViews.js expand to mount hosts, and
mountApplicationViews() renders them before translation and wiring. Markup
tests read the page through a server-side render helper, the i18n scanner
reads view templates, and Vue preserves whitespace so views keep the exact
DOM. No template is converted yet.

src/tooling/applicationHtml.test.mjs

@@ -1,11 +1,17 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import { readFileSync } from 'node:fs';
-import { expandApplicationHtml, APPLICATION_TEMPLATES } from '../../build/application-html.js';
+import {
+  expandApplicationHtml,
+  APPLICATION_TEMPLATES,
+} from '../../build/application-html.js';
+import { APPLICATION_VIEW_NAMES } from '../../build/applicationViews.js';
+import { APPLICATION_VIEWS } from '../ui/views/index.js';
+import { readApplicationHtml } from '../testSupport/applicationHtml.mjs';
 
-test('the standalone document expands every component once and preserves unique element ids', () => {
+test('the standalone document expands every component once and preserves unique element ids', async () => {
   const source = readFileSync(new URL('../../index.html', import.meta.url), 'utf8');
-  const html = expandApplicationHtml(source);
+  const html = await readApplicationHtml();
   assert.equal([...source.matchAll(/gev:template /g)].length, APPLICATION_TEMPLATES.length);
   assert.doesNotMatch(html, /gev:template/);
   const ids = [...html.matchAll(/\sid="([^"]+)"/g)].map(match => match[1]);
@@ -15,8 +21,21 @@ test('the standalone document expands every component once and preserves unique
 });
 
 test('component selection includes only requested markup and refuses filesystem traversal', () => {
-  const html = expandApplicationHtml('<!-- gev:template welcome -->\n');
-  assert.match(html, /id="first-run-launcher"/);
+  const html = expandApplicationHtml('<!-- gev:template hud-loading -->\n');
+  assert.match(html, /id="loading-screen"/);
   assert.doesNotMatch(html, /id="cesiumContainer"/);
   assert.throws(() => expandApplicationHtml('<!-- gev:template ../../.env -->'), /Unknown application template/);
 });
+
+test('views expand to mount hosts, the loading screen stays static, and every view is registered', () => {
+  assert.deepEqual(Object.keys(APPLICATION_VIEWS).sort(), [...APPLICATION_VIEW_NAMES].sort());
+  for (const name of APPLICATION_VIEW_NAMES) {
+    assert.ok(APPLICATION_TEMPLATES.includes(name), name);
+    assert.equal(
+      expandApplicationHtml(`<!-- gev:template ${name} -->\n`),
+      `<div class="gev-view" data-gev-view="${name}"></div>\n`,
+    );
+  }
+  // It paints before any script runs.
+  assert.ok(!APPLICATION_VIEW_NAMES.includes('hud-loading'));
+});