Uses superfly/fly-pr-review-apps to automatically deploy PR preview
environments. A separate fly.preview.toml omits the [build] image
section so the Dockerfile is used to build the PR's code rather than
pulling the production image.

https://claude.ai/code/session_01VBL9BP4oFmJkBQbyMzJz8j

diff --git a/.github/workflows/preview.yml b/.github/workflows/preview.yml
new file mode 100644
index 0000000..93981e5
--- /dev/null
+++ b/.github/workflows/preview.yml
@@ -0,0 +1,27 @@
+name: Preview
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, closed]
+
+env:
+  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+  FLY_REGION: sjc
+  FLY_ORG: personal
+
+jobs:
+  preview:
+    runs-on: ubuntu-latest
+    concurrency:
+      group: pr-${{ github.event.number }}
+    environment:
+      name: pr-${{ github.event.number }}
+      url: ${{ steps.deploy.outputs.url }}
+    steps:
+      - uses: actions/checkout@v6
+      - name: Deploy preview
+        id: deploy
+        uses: superfly/fly-pr-review-apps@1.5.0
+        with:
+          config: fly.preview.toml
+          memory: 256
diff --git a/fly.preview.toml b/fly.preview.toml
new file mode 100644
index 0000000..5dd70a4
--- /dev/null
+++ b/fly.preview.toml
@@ -0,0 +1,21 @@
+app = 'ketchup-preview'
+primary_region = 'sjc'
+
+[http_service]
+  internal_port = 9292
+  force_https = true
+  auto_stop_machines = 'stop'
+  auto_start_machines = true
+  min_machines_running = 0
+  processes = ['app']
+
+[[vm]]
+  memory = '1gb'
+  cpu_kind = 'shared'
+  cpus = 1
+  memory_mb = 256
+
+[env]
+  DATABASE_URL = ':memory:'
+  SENTRY_ENV = 'preview'
+  DEFAULT_USER = 'demo@example.com:Demo User'