perf(web): take Angular Material off the startup path (#1931)

Takes Angular Material off the renderer's startup path: renderer.initialBytes
1,596,201 -> 1,344,067 bytes (-252,134, 15.8%) at the branch point; merged with
master, where #1928 lands the form-field defaults per component, the branch
measures 1,345,807 (-188,797, 12.3% against master's baseline). The bundler
keeps each module in one chunk, so one eager import of any export carries the
module's whole code; each item removes the last eager importer of one Material
module.

- EPG progress and update panels: eager host + `@defer (when visible)` view
  with an `@error` notice; the startup spinner is static markup copied from
  mat-spinner.
- LazyMatDialog: the confirm dialog service, player service, parental lock
  prompt and shell actions resolve MatDialog on first use.
- The theme emits tokens for the 21 imported components only, through a
  `$material-components` list and meta.apply; tools/nx/check-material-theme-scope.mjs
  (CI) keeps it in step with the imports in both directions.
- No provideAnimations(): Material 22 animates with CSS and reads
  prefers-reduced-motion itself; apps/electron-backend-e2e/src/material-motion.e2e.ts
  proves dialogs, selects, menus, snack-bars and tooltips animate in and out and
  stop under reduced motion. Its renderer had deferred every DOM removal to the
  end of the tick, so the catalog list now tracks the grid offset from scroll
  events and the player settings panel decides "focus was inside" in a
  microtask, both with specs that detach the view first.
- The snack-bar stays, and with it button, the icon-button chunk and the CDK
  overlay (about 190 KB): root services inject it.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -436,6 +436,11 @@ jobs:
             - name: Validate form-field defaults
               run: pnpm run ui:form-field-defaults:validate
 
+            # m3-theme.scss themes only the Material components the app
+            # imports; a new import without a theme entry renders unthemed.
+            - name: Validate the Material theme scope
+              run: pnpm run styles:material-theme-scope:validate
+
             # Nx rejects a non-parallel task with continuous dependencies, and
             # the Playwright plugin infers serve dependencies only when CI is
             # unset, so this checks both the local and the CI inference.