chore: organize build outputs into bin directory

.gitignore

@@ -33,5 +33,6 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 # Finder (MacOS) folder config
 .DS_Store
 
-# Data
+# Outputs & Inputs
 data
+bin

package.json

@@ -15,7 +15,7 @@
     "typescript": "^5"
   },
   "scripts": {
-    "build:stdio": "bun build ./stdio.ts --compile --outfile stdio",
+    "build:stdio": "bun build ./stdio.ts --compile --outfile bin/stdio",
     "build": "bun build:stdio",
     "prepare": "bun .husky/install.ts"
   },