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.

build/applicationViews.js

@@ -0,0 +1,7 @@
+/**
+ * Application templates that are now Vue views (src/ui/views). Their markers
+ * expand to a mount host instead of static markup, and
+ * `mountApplicationViews()` renders them before the page is wired. The
+ * loading screen stays static so it paints before any script runs.
+ */
+export const APPLICATION_VIEW_NAMES = Object.freeze([]);