Add JS toolchain: TypeScript, ESLint, Prettier, Vitest

package.json declares the project as ESM with NodeNext module resolution,
exposing dist/index.js as the library entry and dist/bin/quack.js as the
CLI binary. Dev dependencies are pinned to exact versions (yarn.lock holds
the integrity hashes per repo policy on hash-pinned external references).
Adds a placeholder src/index.ts and a single smoke test so make check is
not a no-op.

tsconfig.json

@@ -0,0 +1,21 @@
+{
+    "compilerOptions": {
+        "target": "ES2022",
+        "module": "NodeNext",
+        "moduleResolution": "NodeNext",
+        "lib": ["ES2022"],
+        "outDir": "./dist",
+        "rootDir": "./src",
+        "strict": true,
+        "noImplicitOverride": true,
+        "noUncheckedIndexedAccess": true,
+        "esModuleInterop": true,
+        "skipLibCheck": true,
+        "forceConsistentCasingInFileNames": true,
+        "declaration": true,
+        "declarationMap": true,
+        "sourceMap": true,
+        "resolveJsonModule": true
+    },
+    "include": ["src/**/*", "bin/**/*"]
+}