ci: Split workflows into test and conditional publishing

.github/workflows/publish.yml

@@ -1,9 +1,10 @@
 name: Test & Publish on JSR & npm
 
 on:
-  push:
-    branches:
-      - main
+  workflow_run:
+    workflows: ["Test"]
+    types:
+      - completed
 jobs:
   testAndPublish:
     runs-on: ubuntu-latest

.github/workflows/test.yml

@@ -0,0 +1,26 @@
+name: Test
+
+on:
+  push:
+  pull_request:
+jobs:
+  testAndPublish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "22.x"
+          registry-url: "https://registry.npmjs.org"
+      - uses: pnpm/action-setup@v4
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Build & Test
+        run: pnpm build && pnpm test