ops: deploy pairux.com to dev2 on merge

Railway deployed this on push; dev2 does not by itself. The workflow ssh's
to the box and runs /home/anthony/www/pairux.com/deploy-app.sh, which builds
the image from this checkout and restarts the compose stack. Generated by
cli-tools dev2/dev2-site scaffold.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: ralyodio

.github/workflows/deploy-dev2-pairux-com.yml

@@ -0,0 +1,60 @@
+# Ship every merge to dev2, where pairux.com runs since it left Railway (which
+# deployed on merge by itself). The box pulls the merged commit, rebuilds the
+# image(s) from this repo and restarts the compose stack under
+# /home/anthony/www/pairux.com. Generated by cli-tools/dev2/dev2-site scaffold.
+name: Deploy to dev2
+
+on:
+  push:
+    branches: [master]
+  workflow_dispatch:
+    inputs:
+      ref:
+        description: Git ref to deploy (defaults to the pushed commit)
+        required: false
+        type: string
+
+concurrency:
+  group: deploy-dev2
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    steps:
+      # ${{ }} values go through env, never straight into a run: body.
+      - name: Resolve target revision
+        id: rev
+        env:
+          REF: ${{ inputs.ref || github.sha }}
+        run: echo "sha=$REF" >> "$GITHUB_OUTPUT"
+
+      - name: Set up ssh
+        env:
+          SSH_KEY: ${{ secrets.DEV2_SSH_KEY }}
+          KNOWN_HOSTS: ${{ secrets.DEV2_KNOWN_HOSTS }}
+        run: |
+          install -d -m 700 ~/.ssh
+          printf '%s\n' "$SSH_KEY" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          printf '%s\n' "$KNOWN_HOSTS" > ~/.ssh/known_hosts
+          chmod 644 ~/.ssh/known_hosts
+
+      - name: Deploy
+        env:
+          DEV2_USER: ${{ secrets.DEV2_USER }}
+          DEV2_HOST: ${{ secrets.DEV2_HOST }}
+          SHA: ${{ steps.rev.outputs.sha }}
+        run: |
+          ssh -o BatchMode=yes "$DEV2_USER@$DEV2_HOST" \
+            /home/anthony/www/pairux.com/deploy-app.sh "$SHA"
+
+      - name: Verify the site answers
+        run: |
+          for i in $(seq 1 10); do
+            code=$(curl -s -o /dev/null -w '%{http_code}' "https://pairux.com/api/health" || true)
+            case "$code" in 2*|3*|401|403) echo "pairux.com $code"; exit 0;; esac
+            echo "attempt $i: $code"; sleep 10
+          done
+          echo "pairux.com never answered"; exit 1