publish:all: skip versions already on the registry

npm publish --workspaces fails on unchanged packages (flac/mp3@1.1.1 are
already published). Replace it with an inline loop that checks each
workspace + root against the registry via `npm view` and publishes only
new versions — sub-packages first, root last.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dy

package.json

@@ -30,7 +30,7 @@
   "scripts": {
     "test": "node test.js",
     "test:all": "npm test --workspaces && npm test",
-    "publish:all": "npm publish --workspaces && npm publish",
+    "publish:all": "for d in packages/* .; do id=$(node -p \"require('./$d/package.json').name+'@'+require('./$d/package.json').version\"); npm view \"$id\" version >/dev/null 2>&1 && echo \"skip $id\" || (cd \"$d\" && npm publish); done",
     "build": "npm run build --workspaces --if-present"
   },
   "repository": {