chore: add .gitignore, set tsc noEmit so build doesn't drop .js next to sources

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,7 @@
+node_modules/
+dist/
+*.tsbuildinfo
+.DS_Store
+.env
+.env.local
+.vite/

tsconfig.json

@@ -11,6 +11,7 @@
     "noFallthroughCasesInSwitch": true,
     "resolveJsonModule": true,
     "skipLibCheck": true,
+    "noEmit": true,
     "paths": { "@/*": ["./src/*"] }
   },
   "include": ["src"]