Add Flask shopping app with Nomad deployment

Flask app serving the Citti shopping list with SQLite persistence,
per-category item addition, dynamic custom categories, photo upload,
and a post-trip price analysis page.

- Port 9756, DATA_DIR env var for persistent volume in Nomad
- Gitea Actions pipeline builds Docker image and deploys via Nomad API
- Makefile targets: run, install, build, push

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/deploy.yml

@@ -0,0 +1,41 @@
+name: deploy
+
+on:
+  push:
+    branches: [main]
+
+env:
+  IMAGE: gea.i80.dk/hjess/citti
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Login to Gitea registry
+        run: |
+          echo "${{ secrets.GITEA_TOKEN }}" | \
+            docker login gea.i80.dk -u ${{ github.actor }} --password-stdin
+
+      - name: Build & push image
+        run: |
+          docker build \
+            -t ${{ env.IMAGE }}:latest \
+            -t ${{ env.IMAGE }}:${{ github.sha }} .
+          docker push ${{ env.IMAGE }}:latest
+          docker push ${{ env.IMAGE }}:${{ github.sha }}
+
+      - name: Deploy to Nomad
+        env:
+          NOMAD_ADDR: ${{ secrets.NOMAD_ADDR }}
+          NOMAD_TOKEN: ${{ secrets.NOMAD_TOKEN }}
+        run: |
+          JOB_JSON=$(curl -sf "${NOMAD_ADDR}/v1/jobs/parse" \
+            -H "Content-Type: application/json" \
+            -d "{\"JobHCL\": $(jq -Rs . < citti.nomad)}")
+          curl -sf -X POST "${NOMAD_ADDR}/v1/jobs" \
+            -H "X-Nomad-Token: ${NOMAD_TOKEN}" \
+            -H "Content-Type: application/json" \
+            -d "{\"Job\": ${JOB_JSON}}"
+          echo "✓ Deployed"