ci: consolidate workflows into ci.yml

.github/actions/setup-pnpm-node/action.yml

@@ -0,0 +1,18 @@
+name: Setup pnpm + Node
+description: Install pnpm, set up Node.js (pinned via .nvmrc) with pnpm cache, and install dependencies (frozen lockfile)
+
+runs:
+  using: composite
+  steps:
+    - name: Setup pnpm
+      uses: pnpm/action-setup@v4
+
+    - name: Setup Node.js
+      uses: actions/setup-node@v6
+      with:
+        node-version-file: .nvmrc
+        cache: pnpm
+
+    - name: Install dependencies
+      shell: bash
+      run: pnpm install --frozen-lockfile

.github/actions/wait-for-server/action.yml

@@ -0,0 +1,29 @@
+name: Wait for HTTP server
+description: Poll a URL until it responds with a successful status, or fail after a timeout.
+
+inputs:
+  url:
+    description: URL to poll
+    required: true
+  timeout-seconds:
+    description: Maximum seconds to wait
+    required: false
+    default: "90"
+
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      env:
+        URL: ${{ inputs.url }}
+        TIMEOUT: ${{ inputs.timeout-seconds }}
+      run: |
+        for _ in $(seq 1 "$TIMEOUT"); do
+          if curl -sfo /dev/null "$URL"; then
+            echo "Server is up at $URL"
+            exit 0
+          fi
+          sleep 1
+        done
+        echo "Server at $URL did not respond within ${TIMEOUT}s"
+        exit 1