Add automated infrastructure lifecycle management workflow

.github/workflows/lifecycle.yaml

@@ -0,0 +1,42 @@
+---
+name: Scheduled infrastructure management
+on:
+  schedule:
+    - cron: '0 13 * * 1,2,3,4,5'  # launch at 8:00 AM EST
+    - cron: '0 23 * * 1,2,3,4,5' # teardown at 6:00 PM EST
+jobs:
+  launch:
+    if: github.event.schedule == '0 13 * * 1,2,3,4,5'
+    runs-on: ubuntu-latest
+    environment: pulumi
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install Flox
+        uses: flox/install-flox-action@v2
+      - name: Deploy with Pulumi
+        uses: flox/activate-action@v1
+        env:
+          PULUMI_ACCESS_TOKEN: ${{ secrets.PULUMI_ACCESS_TOKEN }}
+        with:
+          command: |
+            cd infrastructure
+            uv run pulumi up --yes
+            nu ping.nu
+  teardown:
+    if: github.event.schedule == '0 23 * * 1,2,3,4,5'
+    runs-on: ubuntu-latest
+    environment: pulumi
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install Flox
+        uses: flox/install-flox-action@v2
+      - name: Dismantle with Pulumi
+        uses: flox/activate-action@v1
+        env:
+          PULUMI_ACCESS_TOKEN: ${{ secrets.PULUMI_ACCESS_TOKEN }}
+        with:
+          command: |
+            cd infrastructure
+            uv run pulumi down --yes