Add CI test to verify that the compose dev setup works

We broke part of it many commits ago and didn't even notice, because we
didn't try to set it up again from scratch.

Author: dutow

.github/workflows/dev-setup.yml

@@ -0,0 +1,61 @@
+name: Dev Setup
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  dev-setup:
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Start dev stack
+        run: make dev-detach
+
+      - name: Wait for Rails to be healthy
+        run: |
+          echo "Waiting for Rails to start..."
+          for i in {1..60}; do
+            if docker compose -f docker-compose.dev.yml exec -T web curl -fs http://localhost:3000/up 2>/dev/null; then
+              echo "Rails is healthy!"
+              exit 0
+            fi
+            echo "Attempt $i/60 - waiting 5s..."
+            sleep 5
+          done
+          echo "Rails failed to start. Showing logs:"
+          docker compose -f docker-compose.dev.yml logs --tail=200 web db
+          exit 1
+
+      - name: Run db-reset while stack is running
+        run: make db-reset
+
+      - name: Wait for web to restart
+        run: |
+          echo "Waiting for web to restart after db-reset..."
+          for i in {1..30}; do
+            if docker compose -f docker-compose.dev.yml exec -T web curl -fs http://localhost:3000/up 2>/dev/null; then
+              echo "Web is healthy after db-reset!"
+              exit 0
+            fi
+            echo "Attempt $i/30 - waiting 5s..."
+            sleep 5
+          done
+          echo "Web failed to restart. Showing logs:"
+          docker compose -f docker-compose.dev.yml logs --tail=200 web db
+          exit 1
+
+      - name: Run RSpec tests
+        run: make test
+
+      - name: Teardown
+        if: always()
+        run: make down