Add multi-platform function adapters and CI workflow

Introduces adapters for Vercel, Netlify Edge, Deno Deploy, and Cloudflare Pages, each with platform-specific entry points and configuration files. Adds a GitHub Actions CI workflow for linting, type checking, and testing. Updates lint scripts to include adapters, improves type annotations in src/index.js, and fixes a type assertion in security tests.

package.json

@@ -20,8 +20,8 @@
     "dev": "wrangler dev",
     "format": "prettier --write src/ test/ *.js *.json",
     "format:check": "prettier --check src/ test/ *.js *.json",
-    "lint": "eslint src/ test/",
-    "lint:fix": "eslint src/ test/ --fix",
+    "lint": "eslint src/ test/ adapters/",
+    "lint:fix": "eslint src/ test/ adapters/ --fix",
     "start": "wrangler dev",
     "test": "vitest",
     "test:coverage": "vitest run --coverage",