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>

package.json

@@ -1,12 +1,19 @@
 {
   "name": "ng-signals-template",
   "version": "0.0.0",
+  "license": "MIT",
+  "engines": {
+    "node": "^22.22.3 || ^24.15.0 || >=26.0.0"
+  },
   "scripts": {
     "ng": "ng",
     "start": "ng serve",
     "build": "ng build",
     "watch": "ng build --watch --configuration development",
-    "test": "ng test"
+    "test": "ng test",
+    "test:coverage": "ng test --coverage",
+    "format": "prettier --write .",
+    "format:check": "prettier --check ."
   },
   "private": true,
   "packageManager": "npm@11.12.1",
@@ -14,7 +21,6 @@
     "@angular/common": "^22.1.0",
     "@angular/compiler": "^22.1.0",
     "@angular/core": "^22.1.0",
-    "@angular/forms": "^22.1.0",
     "@angular/platform-browser": "^22.1.0",
     "@angular/router": "^22.1.0",
     "rxjs": "~7.8.0",