test: Add a test harness for the built card (#2653)

Mounts the card from `dist/` the way Home Assistant does, by URL with a
HACS tag, and asserts the entry stays a facade, that no chunk imports
it, that the browser is served the file unmodified, and that the card
starts up and fetches a language chunk lazily.

Runs in Chromium, Firefox and WebKit, so a change of bundler or minifier
is checked against every engine.

package.json

@@ -72,6 +72,7 @@
     "@vitest/coverage-v8": "^4.1.10",
     "conventional-changelog-conventionalcommits": "^8.0.0",
     "docsify-cli": "^4.4.4",
+    "es-module-lexer": "^2.3.1",
     "eslint": "^9.24.0",
     "eslint-config-prettier": "^9.1.0",
     "jsdom": "^21.1.2",
@@ -193,6 +194,7 @@
     "prune": "knip",
     "test": "vitest run",
     "test:browser": "vitest run --config vitest.browser.config.ts",
+    "test:dist": "vitest run --config vitest.dist.config.ts",
     "coverage": "vitest run --coverage"
   },
   "volta": {