poi-index: extract pipeline (BRouter host) + import job (flagship) + e2e

- poi-extract.sh: PBF download -> osmium tags-filter -> centroid NDJSON +
  manifest, published via the Caddy sidecar at vSwitch-only /poi/*
- osmium-filters.txt + poi-selectors.sql generated from map-core selectors,
  guarded by sync tests so poiCategories stays the single source of truth
- poi-import.sh: checksum verify -> classify into category rows ->
  70% guard (--bootstrap override) -> atomic rename swap; node_exporter
  textfile metric for import outcome
- systemd service+timer units for both halves (monthly, offset)
- cd-infra.yml: ship infrastructure/scripts to the flagship
- e2e: mock /api/pois instead of /api/overpass

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.github/workflows/cd-infra.yml

@@ -43,7 +43,7 @@ jobs:
           host: ${{ secrets.DEPLOY_HOST }}
           username: root
           key: ${{ secrets.DEPLOY_SSH_KEY }}
-          source: "infrastructure/docker-compose.yml,infrastructure/caddy,infrastructure/prometheus/prometheus.yml,infrastructure/loki/loki-config.yml,infrastructure/promtail/promtail-config.yml,infrastructure/postgres/queries.yml,infrastructure/postgres/init-grafana-user.sql,infrastructure/grafana/provisioning,infrastructure/grafana/dashboards"
+          source: "infrastructure/docker-compose.yml,infrastructure/caddy,infrastructure/prometheus/prometheus.yml,infrastructure/loki/loki-config.yml,infrastructure/promtail/promtail-config.yml,infrastructure/postgres/queries.yml,infrastructure/postgres/init-grafana-user.sql,infrastructure/grafana/provisioning,infrastructure/grafana/dashboards,infrastructure/scripts"
           target: /opt/trails-cool
           strip_components: 1