chore: add CI, coverage gates, and fix template hygiene

Wires the previously-inert @vitest/coverage-v8 into the test builder with
measured thresholds, adds a GitHub Actions workflow (format, test, build),
and fixes assorted gaps a cloning team would hit: no LICENSE, no engines/
.nvmrc, an unusable prettier install, a committed local-only settings file,
a dead 0-byte stylesheet, and a broken Karma-era VS Code test/debug config.
Also drops @angular/forms, which nothing in src/ imports.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: ci
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+
+      - uses: actions/setup-node@v5
+        with:
+          node-version-file: .nvmrc
+          cache: npm
+
+      - run: npm ci
+
+      - name: Format
+        run: npm run format:check
+
+      # `ng test` type-checks tsconfig.spec.json and `ng build` type-checks
+      # tsconfig.app.json *including templates* (strictTemplates), so every .ts
+      # file is already type-checked by the steps below. A separate
+      # `tsc --noEmit` step would be redundant.
+      - name: Test
+        run: npm run test:coverage
+
+      - name: Build
+        run: npm run build